The message comes in late at night: We're engaged. The wedding is in June, and we already live together. My mom says we're living in sin. Is she right, or is that just old-fashioned?
Behind a question like this there is usually real love, a real plan to marry, and a real fear of the answer. Many Catholics were handed a rule without a reason. Many Protestants were told to wait but never heard an argument that held up. Here is what the Bible and the Catholic Church teach, why, and the way home for anyone who has already gone further than he meant to.
Short answer: Yes. Sex before marriage is a grave sin. The Catechism defines fornication as "carnal union between an unmarried man and an unmarried woman" and teaches that it "is gravely contrary to the dignity of persons and of human sexuality" (CCC 2353). The Catholic Church teaches that "the sexual act must take place exclusively within marriage" (CCC 2390), and that includes engaged couples and couples who live together (CCC 2350; CCC 2390–2391). The reason is not that sex is bad but that it is so good: it speaks the language of a total, lifelong gift, and only marriage makes that language true. And no one is beyond mercy. Christ forgives every sin we bring to Him.
Key verses on sex and marriage
- "That is why a man leaves his father and mother and clings to his wife, and the two of them become one body." (Genesis 2:24)
- "Therefore what God has joined together, no human being must separate." (Mark 10:9; see Matthew 19:4–6)
- "Avoid immorality. Every other sin a person commits is outside the body, but the immoral person sins against his own body." (1 Corinthians 6:18)
- "Let marriage be honored among all and the marriage bed be kept undefiled, for God will judge the immoral and adulterers." (Hebrews 13:4)
- "Do not awaken, or stir up love until it is ready." (Song of Songs 2:7)
- "Neither do I condemn you. Go, [and] from now on do not sin any more." (John 8:11)
Scripture quotations are from the New American Bible, Revised Edition (NABRE), © 2010, 1991, 1986, 1970 Confraternity of Christian Doctrine, Washington, D.C. Used by permission. All rights reserved.
What Protestants, Critics, and Others Believe
Historic Protestants agree that it is sin. The Westminster Larger Catechism, a standard of Reformed churches, answers the question of what the seventh commandment forbids: "The sins forbidden in the seventh commandment, besides the neglect of the duties required, are, adultery, fornication" (Q. 139). The real differences with Catholics lie in the reasons, in whether marriage is a sacrament, and in the way back after a fall.
"The Bible never forbids sex between two unmarried people who love each other." Some progressive Christians and many secular readers argue that the Bible's sexual laws target adultery, prostitution and exploitation, not a faithful, consenting couple. They point out that porneia, the Greek word behind "fornication," is related to the word for a prostitute, and that Strong's defines it as "harlotry (including adultery and incest); figuratively, idolatry" (Strong's G4202).
"We're engaged, so it's basically marriage." The Catholic Church has stated this view at its strongest herself: "Today there are many who vindicate the right to sexual union before marriage, at least in those cases where a firm intention to marry and an affection which is already in some way conjugal in the psychology of the subjects require this completion, which they judge to be connatural" (Persona Humana 7).
"Living together first is just wise." Many see living together as responsible: you test compatibility, save money, and avoid a bad marriage. On this view a wedding is a piece of paper, and waiting is unrealistic.
The Catholic Church honors what is good in each view: the love, the desire for a marriage that lasts, the fear of divorce. She rejects the conclusion, and she has reasons.
What Catholics Actually Teach
Fornication is a grave sin. "Fornication is carnal union between an unmarried man and an unmarried woman. It is gravely contrary to the dignity of persons and of human sexuality which is naturally ordered to the good of spouses and the generation and education of children" (CCC 2353).
Sex belongs only within marriage. The Catechism teaches that "the sexual act must take place exclusively within marriage. Outside of marriage it always constitutes a grave sin and excludes one from sacramental communion" (CCC 2390).
That includes living together and "trial marriage." Free unions "offend against the dignity of marriage" (CCC 2390). For couples who plan to marry later: "Carnal union is morally legitimate only when a definitive community of life between a man and woman has been established. Human love does not tolerate 'trial marriages.' It demands a total and definitive gift of persons to one another" (CCC 2391).
Engaged couples are called to wait, and to grow. "Those who are engaged to marry are called to live chastity in continence. They should see in this time of testing a discovery of mutual respect, an apprenticeship in fidelity, and the hope of receiving one another from God." "They should reserve for marriage the expressions of affection that belong to married love" (CCC 2350).
Why: sex speaks the language of a total gift. Human sexuality "is realized in a truly human way only if it is an integral part of the love by which a man and woman commit themselves totally to one another until death" (CCC 2361). Pope St. John Paul II put it sharply: "The total physical self-giving would be a lie if it were not the sign and fruit of a total personal self-giving, in which the whole person, including the temporal dimension, is present" (Familiaris Consortio 11). Outside marriage, the body says "forever" while the life still says "maybe."
Why: a child deserves a mother and father bound to each other. "The spouses' union achieves the twofold end of marriage: the good of the spouses themselves and the transmission of life" (CCC 2363). The act that can bring a new person into the world belongs where that child's mother and father have already promised, publicly and for life, to stay together. (This is never a judgment on any child; every child is willed and loved by God.)
Why: chastity is freedom. "Chastity includes an apprenticeship in self-mastery which is a training in human freedom": "either man governs his passions and finds peace, or he lets himself be dominated by them and becomes unhappy" (CCC 2339).
What Catholics do not teach:
- That sex is dirty. Within marriage, the acts by which spouses unite "are noble and honorable" (CCC 2362). The Catholic Church says no to sex outside marriage because she says a great yes to it within marriage.
- That attraction is a sin. The sin of lust is "disordered desire for or inordinate enjoyment of sexual pleasure" (CCC 2351), not the natural attraction between a man and a woman.
- That we can judge any person's soul. The Catechism says "we must entrust judgment of persons to the justice and mercy of God" (CCC 1861; see the FAQ on mortal sin).
- That anyone is beyond forgiveness, or that a couple living together cannot marry in the Catholic Church (see Objection (f) and the FAQ).
It all points to Christ. St. Paul says the one-flesh union of husband and wife "is a great mystery, but I speak in reference to Christ and the church" (Ephesians 5:32). Jesus gave Himself to His Bride totally, publicly, faithfully and forever. The marriage bed is meant to say the same thing in the language of the body, and chastity is learning to love the way He loves. When we fail, His mercy is the way back.
The Biblical Case
1. From the beginning, God joined the one-flesh union to marriage
The first words Scripture speaks about sexual union place it inside a covenant: "That is why a man leaves his father and mother and clings to his wife, and the two of them become one body" (Genesis 2:24). The order matters: leaving, clinging to a wife, then one body. Jesus quotes this text and draws the conclusion: "So they are no longer two but one flesh. Therefore what God has joined together, no human being must separate" (Mark 10:8–9; see Matthew 19:4–6). "One flesh" is not something two people try out. It is something God does, and it is permanent, so it cannot rightly be entered by two people still free to walk away.
2. Jesus names porneia among the evils that defile, separately from adultery
"For from the heart come evil thoughts, murder, adultery, unchastity, theft, false witness, blasphemy" (Matthew 15:19). In St. Mark: "From within people, from their hearts, come evil thoughts, unchastity, theft, murder, adultery," and "All these evils come from within and they defile" (Mark 7:21–23). The NABRE's "unchastity" translates porneia (its note says St. Matthew reduces St. Mark's list to "seven that partially cover the content of the Decalogue"). Adultery appears in the same list as a separate sin, so porneia cannot simply mean adultery. Thayer's Greek lexicon defines it as "illicit sexual intercourse in general" and notes that "it is distinguished from μοιχεία [adultery] in Matthew 15:19" (Thayer's, G4202).
3. St. Paul's answer to desire between the unmarried is marriage
St. Paul quotes the Corinthians' letter, "It is a good thing for a man not to touch a woman," and answers: "but because of cases of immorality every man should have his own wife, and every woman her own husband" (1 Corinthians 7:1–2). To the unmarried: "but if they cannot exercise self-control they should marry, for it is better to marry than to be on fire" (1 Corinthians 7:8–9). If sex between two unmarried people in love were fine, this counsel would make no sense. St. Paul gives two options: self-control or a wedding. He even addresses a man and "his virgin" (the NABRE note lists an engaged couple among the possible meanings): if "a critical moment has come," then "He is committing no sin; let them get married" (1 Corinthians 7:36).
4. Your body belongs to the Lord, and the act always speaks
"The body, however, is not for immorality, but for the Lord, and the Lord is for the body" (1 Corinthians 6:13). Even a union meant to mean nothing still means something: "[Or] do you not know that anyone who joins himself to a prostitute becomes one body with her? For 'the two,' it says, 'will become one flesh'" (1 Corinthians 6:16). The NABRE note calls such a union "a parody, an antitype of marriage." The act speaks the language of Genesis 2:24 whether we intend it or not. So: "Avoid immorality." "Do you not know that your body is a temple of the holy Spirit within you, whom you have from God, and that you are not your own?" "Therefore, glorify God in your body" (1 Corinthians 6:18–20).
5. Scripture treats sexual immorality as grave
"Do not be deceived; neither fornicators nor idolaters nor adulterers … nor thieves nor the greedy nor drunkards nor slanderers nor robbers will inherit the kingdom of God" (1 Corinthians 6:9–10). "Now the works of the flesh are obvious: immorality, impurity, licentiousness," and "those who do such things will not inherit the kingdom of God" (Galatians 5:19–21). "Immorality or any impurity or greed must not even be mentioned among you, as is fitting among holy ones" (Ephesians 5:3). Sins that exclude from the Kingdom are what the Catholic Church calls grave, or mortal, sins (see Are Mortal and Venial Sins in the Bible?).
6. God's will is your holiness, and even the Law sent desire to marriage
"This is the will of God, your holiness: that you refrain from immorality, that each of you know how to acquire a wife for himself in holiness and honor, not in lustful passion as do the Gentiles who do not know God" (1 Thessalonians 4:3–5; the NABRE note says the phrase about acquiring a wife "has often been interpreted to mean 'control one's body'"). Either reading points to holiness, not passion without commitment. Even the Law of Moses did not treat sex between the unmarried as a private matter: "When a man seduces a virgin who is not betrothed, and lies with her, he shall make her his wife by paying the bride price" (Exodus 22:15; KJV 22:16). The Law's ordinary remedy was marriage (unless her father refused, NABRE 22:16), because the act belongs to marriage.
7. The Old Testament's picture: wait, then pray
The Song of Songs, the Bible's great love poem, repeats a warning: "Do not awaken, or stir up love until it is ready" (Song of Songs 2:7; again at 8:4). The Book of Tobit shows a marriage begun in prayer. On their wedding night Tobiah prays: "Now, not with lust, but with fidelity I take this kinswoman as my wife. Send down your mercy on me and on her, and grant that we may grow old together. Bless us with children" (Tobit 8:7; see 8:4–8). Tobit is one of the seven books Protestant Bibles leave out (see Why Do Catholic Bibles Have 7 More Books?), but its picture is the whole Bible's: fidelity first, then union, all offered to God.
8. Jesus meets sexual sin with truth and mercy together
To the Samaritan woman Jesus said plainly, "For you have had five husbands, and the one you have now is not your husband. What you have said is true" (John 4:18). Jesus did not count that relationship as a marriage, yet she went into the town to tell the people about Him (John 4:28–29). To the woman caught in adultery He said: "Neither do I condemn you. Go, [and] from now on do not sin any more" (John 8:11; the NABRE note on John 7:53–8:11 states, "The Catholic Church accepts this passage as canonical scripture"). Mercy and the call to change always come together.
Objections Answered
(a) "The Bible doesn't explicitly forbid sex between two unmarried people who love each other. Porneia means prostitution or adultery."
At its strongest: Porneia is related to the word for a prostitute, and Strong's gives its sense as "harlotry (including adultery and incest)." No verse says, in modern words, "an engaged couple must not sleep together." A faithful couple in love may fall outside these warnings.
Answer: It is true that no verse uses the phrase "sex before marriage." But a word's root does not fix its meaning; usage does. Thayer's gives porneia as "illicit sexual intercourse in general," and the Topical Lexicon on the same page says, "Its range embraces pre-marital intercourse, prostitution, adultery, homosexual practice, incest, and any other distortion of God's design for sexuality" (G4202). HELPS Word-studies describes it as "promiscuity of any (every) type."
Scripture itself settles the question. Adultery is listed separately from porneia (Matthew 15:19), and adulterers separately from the pornoi (Hebrews 13:4; 1 Corinthians 6:9), so porneia is more than adultery. St. Paul's remedy for porneia among the unmarried is a husband or wife (1 Corinthians 7:2, 9). If his only concern were prostitutes, a steady girlfriend would have solved the problem. He says, "marry." And the positive teaching is explicit: God placed the one-flesh union after the man "clings to his wife" (Genesis 2:24). Scripture does not need to list every way of separating sex from marriage once it has said where sex belongs.
Nor did Christ leave us alone with lexicons. He told His disciples, "Whoever listens to you listens to me" (Luke 10:16), and the Church is "the pillar and foundation of truth" (1 Timothy 3:15; see Is the Church the Pillar and Foundation of Truth?). From the Didache to today, the Catholic Church has read these texts one way.
(b) "We're engaged and committed. That's basically marriage."
At its strongest: The couple has promised lifelong fidelity before God, and in biblical Israel betrothal was already binding. Why should a few months matter?
Answer: Look at the holiest betrothed couple in history. "When his mother Mary was betrothed to Joseph, but before they lived together, she was found with child through the holy Spirit" (Matthew 1:18). The NABRE note explains that "betrothal was the first part of the marriage, constituting a man and woman as husband and wife," and that it "was followed some months later by the husband's taking his wife into his home," "at which time normal married life began." Even a Jewish betrothal, far more binding than a modern engagement, did not begin married life. And an engagement can still be broken: an engaged couple is still free to say "maybe."
The Catholic Church answers the "firm intention" argument directly: "This opinion is contrary to Christian doctrine, which states that every genital act must be within the framework of marriage" (Persona Humana 7). And the Catechism: "However firm the purpose of those who engage in premature sexual relations may be, the fact is that such liaisons can scarcely ensure mutual sincerity and fidelity in a relationship between a man and a woman, nor, especially, can they protect it from inconstancy of desires or whim" (CCC 2391). Engagement is "an apprenticeship in fidelity" (CCC 2350), and waiting is part of the training.
(c) "Living together first is wise. You need to test compatibility."
At its strongest: Marriage is for life, so it is reckless to enter it blind. Living together reveals habits and conflict patterns before the vows, not after.
Answer: The goal is right; the method defeats it. You cannot test a total gift by giving it partially. "Human love does not tolerate 'trial marriages'" (CCC 2391). A trial keeps the exit open, and St. John Paul II explains why that changes everything: "if the person were to withhold something or reserve the possibility of deciding otherwise in the future, by this very fact he or she would not be giving totally" (Familiaris Consortio 11). Every day lived as a trial is practice in loving with one foot out the door, a habit no marriage can afford.
What you really need to know (faith, character, honesty, how someone handles money, anger and family) can be learned by courting well: long conversations, time with each other's families, praying together, and serious marriage preparation. None of it requires sharing a bed. The most revealing test is whether someone is willing to wait for you.
(d) "It's just a piece of paper."
At its strongest: Love is in the heart, not in a government form. God sees the commitment, not the certificate.
Answer: Marriage is not a piece of paper. It is a public covenant, and the public part protects the promise: "the public character of the consent protects the 'I do' once given and helps the spouses remain faithful to it" (CCC 1631). Jesus Himself would not call a relationship without marriage a marriage: "the one you have now is not your husband" (John 4:18). And from the earliest days, the Church had a part in Christian marriage. St. Ignatius of Antioch, writing on his way to martyrdom in Rome, told St. Polycarp: "But it becomes both men and women who marry, to form their union with the approval of the bishop, that their marriage may be according to God, and not after their own lust" (Letter to Polycarp 5).
And if it is only paper, why not sign it? Reluctance to make the promise public usually means the promise is not yet total. For the baptized, marriage is a covenant "raised by Christ the Lord to the dignity of a sacrament" (CCC 1601), with real grace to keep the vows (see What Does the Bible Say About Marriage?). That is not paper; that is God's own help.
(e) "Times have changed. Nobody waits anymore."
At its strongest: People marry later than they once did, and desire has not changed. A rule almost nobody keeps looks like a rule nobody needs.
Answer: Truth is not settled by a vote: "Do not conform yourselves to this age but be transformed by the renewal of your mind" (Romans 12:2). The apostles did not preach chastity to a chaste culture. As the NABRE notes on 1 Corinthians 6:12–20 explain, some in Corinth treated sexual activity as morally neutral, like eating. St. Paul did not lower the standard; he raised their eyes to the Holy Spirit dwelling in their bodies.
And Christians did wait, in a pagan empire as permissive as ours. Around AD 155 St. Justin Martyr told the emperor that "many, both men and women, who have been Christ's disciples from childhood, remain pure at the age of sixty or seventy years" (First Apology 15). It is hard: "Self-mastery is a long and exacting work" (CCC 2342). But "God is faithful and will not let you be tried beyond your strength; but with the trial he will also provide a way out, so that you may be able to bear it" (1 Corinthians 10:13). Self-control is a fruit of the Spirit (Galatians 5:22–23).
(f) "I already have. It's too late for me."
At its strongest: Many people hear "wait until marriage" years after they stopped waiting. The teaching sounds like a door already closed.
Answer: It is never too late. St. Paul wrote to former fornicators: "That is what some of you used to be; but now you have had yourselves washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and in the Spirit of our God" (1 Corinthians 6:11). You can pray today: "A clean heart create for me, God; renew within me a steadfast spirit" (Psalm 51:12; KJV 51:10).
Christ gave His apostles power to forgive sins in His name: "Whose sins you forgive are forgiven them" (John 20:23). The Catechism notes that the Fathers of the Church present confession as "the second plank [of salvation] after the shipwreck which is the loss of grace" (CCC 1446). If you are Catholic, go to confession and begin again (see Why Do Catholics Confess to a Priest?). If you have never been baptized, "By Baptism all sins are forgiven" (CCC 1263). If you are a baptized Christian who is not yet Catholic, your parish will walk you into the Catholic Church and her sacraments of mercy.
Many Catholics call this secondary chastity, or secondary virginity: you cannot undo the past, but you can choose purity from today forward, and God honors that choice. Expect a struggle. "Chastity has laws of growth which progress through stages marked by imperfection and too often by sin" (CCC 2343). Falling again is not a reason to quit. It is a reason to go back to the mercy that never runs out.
The Early Church Agrees
- The Didache (Didache 2, late 1st century; some scholars date it into the 2nd): Under "the second commandment of the Teaching," it lists "you shall not commit adultery" and, separately, "you shall not commit fornication" (newadvent.org). This early Christian handbook distinguishes fornication from adultery and forbids both.
- The Letter to Diognetus (5; anonymous; date disputed, with estimates from the 2nd century to the early 4th): "They marry, as do all [others]; they beget children; but they do not destroy their offspring. They have a common table, but not a common bed" (newadvent.org). Christians stood out in the pagan world because they kept sex within marriage.
- St. Justin Martyr (First Apology 15, c. AD 153–155): "And many, both men and women, who have been Christ's disciples from childhood, remain pure at the age of sixty or seventy years; and I boast that I could produce such from every race of men" (newadvent.org). St. Justin offers Christian chastity to the emperor as evidence of Christ's grace.
- Tertullian (To His Wife 2.8, c. AD 200–206, before his Montanist period): He praises "the happiness of that marriage which the Church cements, and the oblation confirms, and the benediction signs and seals" (newadvent.org). For the early Church, the joy of married love belonged to a marriage made before God and His Church.
Add St. Ignatius of Antioch, martyred between AD 98 and 117 (quoted above), and the witness runs from the generation of the apostles to Rome and North Africa: Christians married, welcomed children, and did not share a bed outside marriage. This is the faith of the first Christians.
Conclusion
From its first pages the Bible places the one-flesh union inside marriage. Jesus names porneia among the evils that defile. St. Paul tells the unmarried who burn with desire to marry. The first Christians kept their beds for marriage, and the Catholic Church teaches today exactly what she taught then.
This is not a "no" to love. It is a defense of love against its counterfeits. Sex says, "I give you all of myself, forever," and marriage is the only place where that sentence is true. If you are waiting, your waiting is a gift to the person you will marry. If you have not waited, Christ is not finished with you. He is waiting for you in confession, and He makes all things new.
Come home. The Church that has taught chastity since the Didache, and still forgives every repentant sinner in Christ's name, is the Catholic Church. Christ did not found many churches. He founded one, on St. Peter and the apostles (Matthew 16:18), and that Church is the Catholic Church. "It is through Christ's Catholic Church alone, which is the universal help toward salvation, that the fullness of the means of salvation can be obtained" (CCC 816). If you are a baptized Christian, you already share "a certain, although imperfect, communion" with her (CCC 838). Every truth you already hold is a call to the rest of the way. If you are not yet a Christian, we invite you to come and see. Christ is calling you into the Catholic Church.
Your next step: Come to Mass this Sunday at your local Catholic church. You can find one near you at MassTimes.org. Everyone is welcome; if you're not yet Catholic, pray with us but don't receive Communion yet. When you're ready to become Catholic, call the parish office and ask about OCIA, the Order of Christian Initiation of Adults. They will walk you through every step. Read our guide: How Do I Become Catholic? Not ready yet? Get our free pocket guide below and keep learning.
FAQ
Is kissing before marriage a sin? Not in itself. Tenderness and a kiss can express real, chaste love between a dating or engaged couple. The Catechism asks the engaged to "reserve for marriage the expressions of affection that belong to married love" (CCC 2350), so the honest question is whether a given kind of affection belongs to engagement or to marriage, and whether it is stirring up desire that only marriage can rightly fulfill (Song of Songs 2:7). Couples who agree on their limits ahead of time usually find chastity much easier.
We're living together and want to marry in the Catholic Church. What do we do? Call your parish and ask to meet the priest, many months before your hoped-for date. A 1999 resource paper for marriage-preparation ministers from the U.S. bishops' Committee on Marriage and Family (not an official statement of the bishops) notes that "the couple may not be refused marriage solely on the basis of cohabitation." The same paper says many diocesan policies encourage such couples to separate before the wedding, that those who stay together "can be encouraged to live chastely before marriage," and that the Sacrament of Reconciliation is encouraged for the Catholic party as part of preparation (USCCB). The bishops' site ForYourMarriage.org has help for engaged couples. If either of you was married before, say so at the first meeting (see Isn't an Annulment Just Catholic Divorce?).
Is sex before marriage a mortal sin? It is grave matter: outside marriage the sexual act "always constitutes a grave sin and excludes one from sacramental communion" (CCC 2390). For a sin to be mortal it must also be "committed with full knowledge and deliberate consent" (CCC 1857), and "Unintentional ignorance can diminish or even remove the imputability of a grave offense" (CCC 1860). Only God judges the heart, but the path is clear: "Anyone conscious of a grave sin must receive the sacrament of Reconciliation before coming to communion" (CCC 1385).
What if I was pressured or forced? If you were forced, you did not commit this sin. The Catechism calls rape "the forcible violation of the sexual intimacy of another person" (CCC 2356); the wrong belongs entirely to the one who forced you, since sin requires "deliberate consent" (CCC 1857). Pressure and manipulation can also lessen responsibility, as the Catechism notes of "external pressures" (CCC 1860). Please talk to someone you trust, such as a priest or counselor, and if you are in danger, contact local emergency services. God sees what was done to you, and His love for you has not changed.
Sources
Scripture (NABRE, bible.usccb.org): Genesis 2:24; Exodus 22:15–16; Tobit 8:4–8; Psalm 51:12; Song of Songs 2:7; Song of Songs 8:4; Matthew 1:18; Matthew 15:19; Matthew 16:18; Matthew 19:4–6; Mark 7:21–23; Mark 10:8–9; Luke 10:16; John 4:18, 28–29; John 8:1–11; John 20:23; Romans 12:2; 1 Corinthians 6:9–20; 1 Corinthians 7:1–2, 8–9, 36; 1 Corinthians 10:13; Galatians 5:19–23; Ephesians 5:3, 32; 1 Thessalonians 4:3–5; 1 Timothy 3:15; Hebrews 13:4.
Catechism of the Catholic Church (vatican.va): 816, 838; 1263; 1385; 1446; 1601; 1631; 1857, 1860, 1861; 2339, 2342, 2343, 2350, 2351, 2353; 2361, 2362, 2363; 2390, 2391.
Church documents: Sacred Congregation for the Doctrine of the Faith, Persona Humana: Declaration on Certain Questions Concerning Sexual Ethics (December 29, 1975), 7; Pope St. John Paul II, Familiaris Consortio (1981), 11; NCCB Committee on Marriage and Family, Marriage Preparation and Cohabiting Couples (1999), a resource paper, not an official statement of the Committee or the bishops' conference.
Church Fathers: Didache 2; Letter to Diognetus 5; St. Ignatius of Antioch, Letter to Polycarp 5; St. Justin Martyr, First Apology 15; Tertullian, To His Wife 2.8.
Other sources: Strong's G4202 porneia, with Thayer's Greek Lexicon, HELPS Word-studies and Topical Lexicon (Bible Hub); Westminster Larger Catechism, Q. 139; Catholic Encyclopedia (1907–1912) on dating: "Didache", "Epistle to Diognetus", "St. Ignatius of Antioch", "St. Justin Martyr", "Tertullian"; ForYourMarriage.org (an initiative of the United States Conference of Catholic Bishops).