1 Corinthians 6:18

"Flee fornication." He said not, "abstain from fornication," but "Flee:" that is, with all zeal make to yourselves deliverance from that evil. "Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body." This is less than what went before; but since he had to speak of fornicators, he amplifies that guilt by topics drawn from all quarters, from greater things and smaller alike, making the charge heinous. And, in fact, that former topic was addressed to the more religious, but this to the weaker sort. For this also is characteristic of the wisdom of Paul, not only to allege the great things wherewith to abash men, but the lesser also, and the consideration of what is disgraceful and unseemly. "What then," say you, "does not the murderer stain his hand? What, of the covetous person and the extortioner?" I suppose it is plain to every one. But since it was not possible to mention anything worse than the fornicator, he amplifies the crime in another way, by saying that in the fornicator the entire body becomes defiled. For it is as polluted as if it had fallen into a vessel of filth, and been immersed in defilement. And this too is our way. For from covetousness and extortion no one would make haste to go into a bath, but as if nothing had happened returns to his house. Whereas from intercourse with a harlot, as having become altogether unclean, he goes to a bath. To such a degree does the conscience retain from this sin a kind of sense of unusual shame. Both however are bad, both covetousness and fornication; and both cast into hell. But as Paul doeth every thing with good management, so by whatever topics he had he magnified the sin of fornication.