A theme running through the whole Bible focuses on the evils of sexual immorality. Why is this?
Many sins injure other people. Lying, theft, murder, gossip, greed – all injure other people in some way. And of course adultery which is a form of sexual immorality also deeply hurts others.
However can it be said that all sexual immorality injures others? For example, two unmarried people living happily together are committing fornication when they have sex. But who are they hurting? If they are consenting adults then it seems there is no victim in this act.
Or consider prostitution. Why is it wrong for an unmarried man to pay for sex from a woman who is very willing to give sex and receive money?
1 Corinthians 6:18 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 Thessalonians 4:3-5 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;
Ephesians 5:3 But sexual immorality and all impurity or covetousness must not even be named among you, as is proper among saints.
Galatians 5:19 Now the works of the flesh are evident: sexual immorality, impurity, sensuality,
1 Corinthians 7:2 But because of the temptation to sexual immorality, each man should have his own wife and each woman her own husband.
Ephesians 5:5 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.
Revelation 21:8 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.”
Mark 7:20-23 And he said, “What comes out of a person is what defiles him. 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.”