Part 3 of a 4 part series
This is the third article in our series on immorality — and we have saved the subject that most people think of first for now; not because it is the most important, but because without the foundation laid in Parts 1 and 2 — about what immorality is at its root, and how the heart is the battleground — the Bible’s teaching on sexual immorality is easy to misread as a mere list of rules.
This article is written for anyone who wants to understand what the Bible actually teaches about sexual immorality — and for anyone who has personally struggled with it, or loves someone who has. The Bible’s teaching here is serious. And its hope is just as serious.
What Does “Sexual Immorality” Actually Mean in the Bible?
The word that the New Testament uses, over and over, for sexual immorality is the Greek word porneia. The Bauer-Danker Lexicon (BDAG) defines it as any form of sexual intercourse outside the bounds of biblical marriage. That means porneia covers a lot of ground. Paul uses it as an umbrella term that includes:
Adultery — sexual unfaithfulness within marriage. Fornication — sex between unmarried people. Homosexual practice (Romans 1:26–27; 1 Corinthians 6:9–10). Incest (1 Corinthians 5:1). Prostitution (1 Corinthians 6:15–16). Lust cultivated in the heart — Jesus includes this: “everyone who looks at a woman with lust for her has already committed adultery with her in his heart” (Matthew 5:28, NASB2020). Pornography — which the very word identifies as a modern expression of the ancient problem.
Notice that the list is not just about actions. It is also about the interior life — the desires that are entertained, cultivated, and indulged in the mind. As we saw in Parts 1 and 2, Scripture consistently locates the problem not just in what we do with our bodies but in what we allow to happen in our hearts.
❖ Key Point
Porneia is not a narrow category. It covers all sexual activity — and all sexual desire deliberately cultivated — outside the covenant of marriage between one man and one woman. The Bible is specific, and it is comprehensive.
Why Does God Care So Much About This?
The answer begins in the first two chapters of the Bible.
Genesis 2:24 (NASB2020)
“For this reason a man shall leave his father and his mother, and be joined to his wife; and they shall become one flesh.”
The “one flesh” union of Genesis 2:24 is not just a description of physical intimacy. It is a description of two people becoming, in the fullest sense, one — emotionally, spiritually, and physically, within the covenant commitment of marriage. Jesus cited this verse as the permanent, creational standard for marriage when questioned about divorce (Matthew 19:4–6).
But the Apostle Paul takes this even further. In Ephesians 5:31–32, he quotes Genesis 2:24 and then says something remarkable:
Ephesians 5:31–32 (NASB2020)
“For this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh.’ This mystery is great; but I am speaking with reference to Christ and the church.”
Marriage, Paul is saying, is not primarily about the two people in it. It is a picture — a living illustration of Christ’s relationship with His people. When the marriage covenant is violated — whether by adultery, by premarital sex, by lust, or by pornography — it damages the very thing that God designed to show the world something true about His love for humanity.
The Body Is a Temple — What Does That Actually Mean?
1 Corinthians 6:18–20 (NASB2020)
“Flee from sexual immorality. Every other sin that a person commits is outside the body, but the sexually immoral person sins against his own body. Or 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? For you have been bought with a price: therefore glorify God in your body.”
Three things are happening in this passage that are worth unpacking. First: Paul says that sexual immorality is unique in that it sins against the body itself — wounding the very person who commits it at a deep, integrated level. Second: The body is the temple of the Holy Spirit — the dwelling place of God. To use that body for sexual immorality is, in Paul’s framework, to defile a sanctuary. Third: “You are not your own.” The believer’s body belongs to God — purchased by the blood of Christ. This is the consecration argument that Pastor Russell returned to again and again in his writings.
C.T. Russell — On the Consecrated Body
Pastor Russell consistently taught that the consecrated believer has presented the body to God as a living sacrifice (Romans 12:1) and may not use it for any purpose foreign to the Lord’s service. Sexual immorality is therefore not merely a moral failure but a breach of the covenant of consecration — a form of spiritual infidelity. The body is the temple of the Holy Spirit (1 Corinthians 6:19); to defile it is to profane what God has set apart as sacred.
Pastor Russell’s documented position on the consecrated body is drawn from: Studies in the Scriptures, Vol. VI, The New Creation (1904). Public domain; archive.org.
What Does the Bible Say About the Consequences?
Scripture is honest and direct about the consequences of sexual immorality — and it is worth hearing them clearly, not to produce shame, but to understand why this matters so much.
Spiritual consequences. Repeated, unrepentant sexual immorality is described by Paul as incompatible with inheriting the kingdom of God (1 Corinthians 6:9–10; Galatians 5:19–21). Paul is describing those who habitually, persistently engage in sexual immorality without repentance, not those who have fallen, repented, and are fighting to walk in purity. But the warning is real and serious.
Personal consequences. Paul notes in 1 Corinthians 6:18 that sexual sin uniquely damages the person who commits it — in terms of shame, relational difficulty, distorted thinking, and a diminished capacity for intimacy. The Bible acknowledges all of this as real.
Consequences for others. Paul adds in 1 Thessalonians 4:6 that sexual immorality involves “violating and exploiting” another person. Sexual sin is never truly private. It always involves another person — whether directly, or through the relational and spiritual damage that ripples outward into marriages, families, and communities.
Biblical examples. David’s adultery with Bathsheba (2 Samuel 11–12) led to deception, murder, and consequences that marked his household for the rest of his life. Samson’s entanglement with Delilah cost him his consecration, his eyes, his freedom, and ultimately his life (Judges 16).
The Positive Call: What Sexual Purity Actually Looks Like
The Bible’s call to sexual purity is positive before it is prohibitive. Hebrews 13:4 is a good example: “Marriage is to be held in honor among all, and the marriage bed is to be undefiled” (NASB2020). The first half of that sentence is not a prohibition — it is an affirmation. And Proverbs 5:18–19 goes even further, celebrating the joy and delight of sexual intimacy within the marriage covenant as one of God’s good gifts.
Flee, don’t negotiate. Paul’s word is “flee” — the same language used of Joseph running from Potiphar’s wife (Genesis 39:12). Not “manage carefully.” The first strategy against sexual temptation is active, decisive avoidance.
Guard the mind. Paul’s prescription in Philippians 4:8 — actively filling the mind with “whatever is true, whatever is honorable, whatever is right, whatever is pure” — is the positive counterpart to fleeing. The battle is won or lost in the thought life long before it becomes a physical battle.
Don’t fight alone. Sexual immorality thrives in secrecy. Accountability — honest, grace-filled, and not shame-based — is one of the most consistent features of long-term freedom from sexual sin. James 5:16: “Confess your sins to one another, and pray for one another so that you may be healed.”
Get help if you need it. For patterns of sexual sin that have become deeply entrenched, pastoral care and, where appropriate, professional Christian counseling are not a sign of weak faith. They are wisdom.
The Hope: “Such Were Some of You”
1 Corinthians 6:9–11 (NASB2020)
“Or do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived: neither the sexually immoral, nor idolaters, nor adulterers, nor homosexuals… will inherit the kingdom of God. Such were some of you; but you were washed, but you were sanctified, but you were justified in the name of the Lord Jesus Christ and in the Spirit of our God.”
Read that last sentence again. Such were some of you. Past tense. Three verbs describing three complete realities: Washed — the guilt of the past is removed. Sanctified — set apart as holy to God, a new identity, not a behavioral improvement program. Justified — declared righteous. The righteousness of Christ is credited to the person who trusts in Him.
✦ GOOD NEWS
No form of sexual immorality — however long it has continued, however deep its roots, however much damage it has caused — is beyond the reach of this washing, this sanctification, this justification. The gospel’s power to restore is as complete as its diagnosis is honest.
No form of sexual immorality — however long it has continued, however deep its roots, however much damage it has caused — is beyond the reach of this washing, this sanctification, this justification. The gospel’s power to restore is as complete as its diagnosis is honest.
A Word to the Church: Truth and Grace Together
Sexual immorality is not a subject the church can simply avoid — because the people in the church are wrestling with it, and they need the truth in order to navigate it faithfully. But truth delivered without grace produces condemnation, not repentance. And grace declared without truth produces license, not freedom.
Coming Up Next
In Part 4 of this series, we examine this more fully: the church’s responsibility when immorality enters its midst, how the Matthew 18 process works in practice, the crucial distinction between the unrepentant and the struggling, and the goal that must never be lost — not punishment, but restoration.
Part 3 – You Are Here
About This Series
This 4-part series explores Immorality as the Bible presents it — in three interconnected dimensions: everyday morality, spiritual morality, and sexual morality— and concludes with the Church’s responsibility. Each article is grounded in NASB2020 Scripture, the writings of C.T. Russell, the Herald Magazine, and the Harvest Truth Database (HTDB).
All Scripture: New American Standard Bible 2020 (NASB2020)
