Sexual immorality begins with the lustful attitudes of our sinful natures. It is rooted in the darkness within us. Therefore sexual immorality, like other sins that enslave unbelievers, will incur God’s wrath. Our bodies were not meant for sexual immorality, but for the Lord who has created us and called us to live in sexual purity. His will is that every Christian be sexually pure, in his thoughts and his words as well as in his actions. Therefore it is holy and honorable to completely avoid sexual immorality, to repent of it, to flee from it, and to put it to death in our lives, as we live by the Spirit. We’ve spend enough time living like pagans in passionate lust. We should not be in close association with another Christian who persists in sexual immorality.For this is the will of God, your sanctification: that you abstain from sexual immorality; (1 Thessalonians 4:3)

But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart.
(Matthew 5:28)

For from within, out of the heart of man, come evil thoughts, sexual immorality, theft, murder, adultery, coveting, wickedness, deceit, sensuality, envy, slander, pride, foolishness. All these evil things come from within, and they defile a person.”
(Mark 7:21-23)

The night is far gone; the day is at hand. So then let us cast off the works of darkness and put on the armor of light. Let us walk properly as in the daytime, not in orgies and drunkenness, not in sexual immorality and sensuality, not in quarreling and jealousy.
(Romans 13:12-13)

that you abstain from what has been sacrificed to idols, and from blood, and from what has been strangled, and from sexual immorality. If you keep yourselves from these, you will do well. Farewell.”
(Acts 15:29)

But now I am writing to you not to associate with anyone who bears the name of brother if he is guilty of sexual immorality or greed, or is an idolater, reviler, drunkard, or swindler–not even to eat with such a one.
(1 Corinthians 5:11)

“Food is meant for the stomach and the stomach for food”–and God will destroy both one and the other. The body is not meant for sexual immorality, but for the Lord, and the Lord for the body.
(1 Corinthians 6:13)

Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body.
(1 Corinthians 6:18)

I fear that when I come again my God may humble me before you, and I may have to mourn over many of those who sinned earlier and have not repented of the impurity, sexual immorality, and sensuality that they have practiced.
(2 Corinthians 12:21)

But I say, walk by the Spirit, and you will not gratify the desires of the flesh. For the desires of the flesh are against the Spirit, and the desires of the Spirit are against the flesh, for these are opposed to each other, to keep you from doing the things you want to do. But if you are led by the Spirit, you are not under the law. Now the works of the flesh are evident: sexual immorality, impurity, sensuality, idolatry, sorcery, enmity, strife, jealousy, fits of anger, rivalries, dissensions, divisions, envy, drunkenness, orgies, and things like these. I warn you, as I warned you before, that those who do such things will not inherit the kingdom of God.
(Galatians 5:16-21)

But sexual immorality and all impurity or covetousness must not even be named among you, as is proper among saints. Let there be no filthiness nor foolish talk nor crude joking, which are out of place, but instead let there be thanksgiving. For you may be sure of this, that everyone who is sexually immoral or impure, or who is covetous (that is, an idolater), has no inheritance in the kingdom of Christ and God.
(Ephesians 5:3-5)

Put to death therefore what is earthly in you: sexual immorality, impurity, passion, evil desire, and covetousness, which is idolatry. On account of these the wrath of God is coming.
(Colossians 3:5-6)

For this is the will of God, your sanctification: that you abstain from sexual immorality; that each one of you know how to control his own body in holiness and honor, not in the passion of lust like the Gentiles who do not know God; that no one transgress and wrong his brother in this matter, because the Lord is an avenger in all these things, as we told you beforehand and solemnly warned you. For God has not called us for impurity, but in holiness.
(1 Thessalonians 4:3-7)

Let marriage be held in honor among all, and let the marriage bed be undefiled, for God will judge the sexually immoral and adulterous.
(Hebrews 13:4)

For the time that is past suffices for doing what the Gentiles want to do, living in sensuality, passions, drunkenness, orgies, drinking parties, and lawless idolatry.
(1 Peter 4:3)

just as Sodom and Gomorrah and the surrounding cities, which likewise indulged in sexual immorality and pursued unnatural desire, serve as an example by undergoing a punishment of eternal fire.
(Jude 1:7)

But I have a few things against you: you have some there who hold the teaching of Balaam, who taught Balak to put a stumbling block before the sons of Israel, so that they might eat food sacrificed to idols and practice sexual immorality.
(Revelation 2:14)

But as for the cowardly, the faithless, the detestable, as for murderers, the sexually immoral, sorcerers, idolaters, and all liars, their portion will be in the lake that burns with fire and sulfur, which is the second death.”
(Revelation 21:8)