Sexual Sin: What the Bible Really Says

Sexual Sin: What the Bible Really Says

Introduction: A Crisis of Clarity

Few topics in the church today are as controversial—or as muddied—as sexual morality. Modern culture pressures believers to either revise or soften biblical teachings to fit contemporary values. Meanwhile, many churches avoid the subject entirely, hoping silence will preserve peace. But silence never produces righteousness.

The Bible speaks clearly and consistently from beginning to end: sexual immorality (πορνεία / porneia, Strong’s G4202) is a sin, and one that separates people from God both in this life and eternally if left unrepented. The New Testament writers, particularly Paul, do not introduce new ideas—they affirm and quote directly from the Greek Old Testament (LXX), carrying forward what was revealed in Genesis, Leviticus, and beyond. And Revelation gives the final word: the sexually immoral do not inherit the kingdom of God.

This article aims to define sexual immorality biblically, explain key terms, refute modern objections, and call all who are willing to the grace of repentance and restoration in Christ.

A Biblical Catalog of Sexual Sin: More Than Just One Issue

One of the most common mistakes in modern conversations about sexual morality is narrowing the conversation to homosexuality alone. While the culture has certainly forced that issue into the spotlight, the Bible does not isolate or prioritize one kind of sexual sin over another. It treats all sexual immorality (πορνεία / porneia) as sinful—whether heterosexual or homosexual, public or private, habitual or one-time. There is no room for self-righteousness here.

God’s Word is an equal-opportunity offender when it comes to sexual sin. It exposes every heart, unmasks every lust, and calls all people—regardless of orientation or history—to repentance, purity, and holy conduct in body and soul.

Below is a biblical breakdown of sexual sins commonly addressed in Scripture, along with the Greek terms, definitions, and the verses that deal with them explicitly.

1. Fornication (Sex Outside of Marriage) — πορνεία (porneia) [G4202]

Definition: Any sexual intercourse outside of biblical marriage.

• Scripture:

  • “God’s will is for you to be holy, so stay away from all sexual sin.” (1 Thessalonians 4:3, NLT)

  • Greek: ἀπέχεσθαι ὑμᾶς ἀπὸ τῆς πορνείας — “that you abstain from sexual immorality” (LEB).

• Context Note: This includes premarital sex, casual sex, and even consensual relationships outside covenant marriage. Scripture does not support the idea of “test-driving” sexual compatibility.

2. Adultery — μοιχεία (moicheia) [G3430]

Definition: Sexual activity between a married person and someone who is not their spouse.

• Scripture:

  • “You must not commit adultery.” (Exodus 20:14, NLT)

  • “Let marriage be held in honor... and let the marriage bed be undefiled, for God will judge sexually immoral people and adulterers.” (Hebrews 13:4, LEB)

• Greek Terms:

  • μοιχοί (moichoi) — adulterers

  • μοιχεία (moicheia) — adultery

• Context Note: Jesus elevated this command in Matthew 5:27–28, making even lust of the heart an offense before God.

3. Homosexual Practice — ἀρσενοκοῖται (arsenokoitai) [G733] & μαλακοί (malakoi) [G3120]

Definition: Men engaging in sexual activity with men (arsenokoitai) and those who adopt passive or effeminate roles (malakoi).

• Scripture:

  • “Don’t fool yourselves. Those who indulge in sexual sin, or who worship idols, or commit adultery, or are male prostitutes (malakoi), or practice homosexuality (arsenokoitai)... none of these will inherit the Kingdom of God.” (1 Corinthians 6:9–10, NLT)

• Context Note: These two terms, used together, eliminate the idea that only abusive or coercive homosexuality is condemned.

4. Lust — ἐπιθυμέω (epithumeō) [G1937]

Definition: Intense desire or craving, especially sexual in nature.

• Scripture:

  • “Anyone who even looks at a woman with lust has already committed adultery with her in his heart.” (Matthew 5:28, NLT)

• Greek Word:

  • ἐπιθυμέω — to set one’s heart upon; to covet or desire intensely.

• Context Note: Lust is not merely a temptation—it is sin when welcomed or entertained.

5. Incest — ἀκαθαρσία (akatharsia) [G167] and Forbidden Unions

Definition: Sexual relations with a close relative, violating familial boundaries.

• Scripture:

  • Leviticus 18 lists multiple categories of forbidden relationships.

  • 1 Corinthians 5:1 condemns a man for having his father’s wife — Paul demands removal from the congregation.

• Greek Word:

  • ἀκαθαρσία — impurity, uncleanness, often used in connection with perverse sexual conduct.

6. Prostitution / Transactional Sex — πόρνη (pornē) [G4204]

Definition: Engaging in or paying for sex as a transaction.

• Scripture:

  • “Don’t you realize that your bodies are actually parts of Christ? Should a man take his body... and join it to a prostitute? Never!” (1 Corinthians 6:15, NLT)

• Greek Word:

  • πόρνη — prostitute; πόρνος — fornicator (male).

• Context Note: Paul emphasizes not just the act but the spiritual reality: “He who is joined to a prostitute becomes one body with her” (1 Cor. 6:16).

7. Bestiality — No Greek Word Preserved, But Clearly Forbidden

Scripture:

• “A man must never have sexual relations with an animal... and a woman must never present herself to a male animal to have intercourse with it.” (Leviticus 18:23, NLT)

• Context Note: While no specific Greek term exists in the New Testament for this, the Old Testament is unequivocal. It is included in lists of detestable practices that “defile the land.”

8. Rape / Coercion — Condemned as a Violation of Personhood

Scripture Examples:

• Deuteronomy 22:25–27 lays out severe punishment for a man who violates a woman by force.

• 2 Samuel 13 – Amnon’s rape of Tamar is treated as a heinous act, bringing disgrace and destruction.

• Context Note: While the ancient legal penalties vary, the moral standard remains: sexual activity must be consensual within covenant marriage. Anything else is evil.

9. Pornography — Modern, but Biblically Addressed via Lust and Voyeurism

Scripture Principles:

• “Don’t set your heart on her beauty or let her glance captivate you.” (Proverbs 6:25)

• “I made a covenant with my eyes not to look with lust at a young woman.” (Job 31:1, NLT)

• Greek Connection: While pornographia is a modern term, it shares the root with πορνεία. Viewing sexual content for gratification is lust—a sin of the eyes and heart.

Conclusion: God Is Clear, Culture Is Not

Contrary to modern revisionism, the Bible does not give us a vague moral compass open to cultural negotiation. The Greek is clear. The terms are precise. The Scriptures are consistent.

Sexual sin is not a peripheral issue in the Christian life—it’s often the front line of spiritual warfare, personal discipline, and cultural compromise. But God’s grace is deeper still.

As Paul wrote to the Corinthians—after listing every kind of sexual sin:

“Some of you were once like that. But you were cleansed; you were made holy; you were made right with God...” (1 Corinthians 6:11, NLT)

There is no sin so deep that Christ cannot redeem. But there is also no repentance where sin is excused. The gospel calls all of us to surrender—not to our desires, but to our Savior.

I. Greek Terms for Sexual Sin

1. πορνεία (porneia) — Strong’s G4202

• Definition: illicit sexual intercourse; fornication, adultery, homosexuality, incest, prostitution, or any unlawful sexual conduct.

• Used by Jesus in Matthew 15:19:

  
  

  “From the heart come evil thoughts, murder, adultery, all sexual immorality (πορνεῖαι), theft, lying, and slander.” (NLT)

• Context Note: Jesus includes porneia as a moral category in line with murder and lying—clearly not cultural or ceremonial.

2. ἀρσενοκοῖται (arsenokoitai) — Strong’s G733

• Definition: from arsēn (male) and koitē (bed); men who have sex with men.

• Appears in:

  • 1 Corinthians 6:9

  • 1 Timothy 1:10

• Important Note: Paul appears to coin this term directly from the Septuagint translation of Leviticus 18:22 and 20:13, which forbids “a man lying with a man as with a woman.” This is not vague or ambiguous; the Greek phrasing is unmistakable.

3. μαλακοί (malakoi) — Strong’s G3120

• Definition: soft, effeminate, often interpreted as men who are sexually passive, especially in homosexual acts.

• Appears in 1 Corinthians 6:9, often paired with arsenokoitai.

II. Biblical Foundations – Old and New Testament Unity

Genesis 19 – The Sin of Sodom

“But the men of Sodom, both young and old, came from all over the city and surrounded the house. They shouted to Lot, ‘Where are the men who came to spend the night with you? Bring them out to us so we can have sex with them!’” (Genesis 19:4–5, NLT)

Context Note: Some argue Sodom’s sin was merely a lack of hospitality. However, the demand is explicitly sexual. Jude 7 confirms this: “...Sodom and Gomorrah...indulged in sexual immorality and pursued unnatural desire.”

Leviticus 18:22; 20:13 (LXX & Paul’s Use)

“You shall not lie with a male as with a woman; it is an abomination.” (Leviticus 18:22, LEB)

Paul reflects this language in arsenokoitai, connecting the Law’s moral standard with the New Testament church. He does not distance himself from it—he reinforces it.

III. The Apostle Paul’s Clarity

Romans 1:24–27

“God abandoned them to their shameful desires. Even the women turned against the natural way to have sex and instead indulged in sex with each other. And the men, instead of having normal sexual relations with women, burned with lust for each other.” (Romans 1:26–27, NLT)

Context Note: Paul references sins that began in humanity’s earliest history, not merely his cultural moment. This is not “first-century opinion”—Paul describes a regression from God’s design that spans all time. Romans 1:20 even says these truths are “clearly seen” in creation.

IV. Future Judgment – Revelation’s Warnings

Revelation 21:8

“But cowards, unbelievers, the corrupt, murderers, the immoral (pornois), those who practice witchcraft, idol worshipers, and all liars—their fate is in the fiery lake of burning sulfur. This is the second death.” (NLT)

Greek Word: πόρνοι (pornoi, plural of porneia)Context Note: This isn’t about ancient cultures. Revelation speaks of the future judgment. The sexually immoral will not enter the New Heaven and New Earth.

V. Common Objections Refuted

1. “Jesus Never Mentioned Homosexuality”

False. Jesus condemned porneia (Matt. 15:19), which includes all sexual sin. He also affirmed marriage as being male and female (Matthew 19:4–6).

2. “That Was Cultural”

Romans 1 explicitly refers to humanity’s earliest sins. Revelation points forward to final judgment. Paul quotes the Greek Old Testament, not cultural Roman law.

3. “Arsenokoitai is Mistranslated”

This is a fabricated objection. The word is built from Leviticus’s Greek, combining arsēn (male) and koitē (bed). Its meaning is plain and consistent.

4. “Love is Love”

Biblically, love obeys God’s commands (John 14:15). God defines love in terms of righteousness, not human desire.

VI. Grace and Restoration

The gospel never ends with condemnation. Paul himself wrote:

“Some of you were once like that. But you were cleansed; you were made holy; you were made right with God by calling on the name of the Lord Jesus Christ.”(1 Corinthians 6:11, NLT)

The church must not affirm sin, but neither must we forget that Jesus came to save sinners. Sexual immorality—like all sin—can be forgiven, but not while being justified or celebrated.

Conclusion: Truth and Mercy Together

The Bible’s teaching on sexual immorality is not outdated. It is clear, consistent, and rooted in God's unchanging character. From Genesis to Revelation, the standard remains: sexuality belongs in marriage between one man and one woman, and anything outside that is sin.

Yet within that truth is a stunning offer of mercy. The same Jesus who warned of judgment also said, “Come to me, all who are weary... and I will give you rest.” (Matthew 11:28). The arms of grace remain open—but only to those who come on His terms.