Every sin is bad. Every sin corrupts. Saying a little white lie will send you to hell just as equally as a fornicating sin will. However, sexual immorality goes a bit deeper. Sexual immorality cuts to the core of humans in a way that other sins do not. The reason is simple: it’s intertwined with the heart and soul and mind, as well as with the body. Not every sin is like that. That’s what Paul means in 1 Corinthians 6:18 when he says that every other sin is outside the body, but the sexual immoral person sins against his own body. To sin sexually, Paul might say today, means you are practically going to ruin your life (here on earth, not just in eternity).
John Calvin explains it like this: “[Paul] does not altogether deny that there are other vices, in like manner, by which our body is dishonored and disgraced, but that his meaning is simply this — that defilement does not attach itself to our body from other vices in the same way as it does from fornication. My hand, it is true, is defiled by theft or murder, my tongue by evil speaking, or perjury, and the whole body by drunkenness; but fornication leaves a stain impressed upon the body, such as is not impressed upon it from other sins.”
Sexual immorality has a way of tearing apart lives and relationships in a way that other sins do not. This doesn’t excuse other sins. This doesn’t mean that obscene pride and outrageous lifestyles will not ruin a life. O, they will! But a plain reading of Scripture reveals this truth especially about sexual immorality. Proverbs 5:8-11 teaches us, “Keep your way far from her [that is, the forbidden woman, v. 3], and do not go near the door of her house, lest you give your honor to others and your years to the merciless, lest strangers take their fill of your strength, and your labors go to the house of a foreigner, and at the end of your life you groan, when your flesh and body are consumed.”
There is hope amidst this dismal picture. The good news of the gospel is that Christ’s blood has redeemed you. Your sexual purity is a blood-bought gift that was purchased on Calvary. Know that God owns your body, and he has made it for himself, for holiness. What better incentive is there to kill sexual sin (as well as every sin)!
Sexual immorality will consume your flesh and your body and your heart and your mind in an all-together differently destructive way than every other sin. Paul teaches that. Proverbs does, too. It’s all over Scripture. Every other sin is outside your body. Sexual sin is against your own body. Flee sexual immorality. Please, it will save you from ruining your life.