1 Corinthians 6:12

The twelfth verse and former part of the thirteenth seem to relate to that early dispute among Christians about the distinction of meats, and yet to be prefatory to the caution that follows against fornication. The connection seems plain enough if we attend to the famous determination of the apostles, Acts 15, where the prohibition of certain foods was joined with that of fornication. Now some among the Corinthians seem to have imagined that they were as much at liberty in the point of fornication as of meats, especially because it was not a sin condemned by the laws of their country. They were ready to say, even in the case of fornication, All things are lawful for me. This pernicious conceit Paul here sets himself to oppose: he tells them that many things lawful in themselves were not expedient at certain times, and under particular circumstances; and Christians should not barely consider what is in itself lawful to be done, but what is fit for them to do, considering their profession, character, relations, and hopes: they should be very careful that by carrying this maxim too far they be not brought into bondage, either to a crafty deceiver or a carnal inclination. All things are lawful for me, says he, but I will not be brought under the power of any, Co1 6:12.

— Matthew Henry's Concise Commentary (public domain)

REFUTATION OF THE ANTINOMIAN DEFENSE OF FORNICATION AS IF IT WAS LAWFUL BECAUSE MEATS ARE SO. (Co1 6:12-20) All things are lawful unto me--These, which were Paul's own words on a former occasion (to the Corinthians, compare Co1 10:23, and Gal 5:23), were made a pretext for excusing the eating of meats offered to idols, and so of what was generally connected with idolatry (Act 15:29), "fornication" (perhaps in the letter of the Corinthians to Paul, Co1 7:1). Paul's remark had referred only to things indifferent: but they wished to treat fornication as such, on the ground that the existence of bodily appetites proved the lawfulness of their gratification. me--Paul giving himself as a sample of Christians in general. but I--whatever others do, I will not, &c. lawful . . . brought under the power--The Greek words are from the same root, whence there is a play on the words: All things are in my power, but I will not be brought under the power of any of them (the "all things"). He who commits "fornication," steps aside from his own legitimate power or liberty, and is "brought under the power" of an harlot (Co1 6:15; compare Co1 7:4). The "power" ought to be in the hands of the believer, not in the things which he uses [BENGEL]; else his liberty is forfeited; he ceases to be his own master (Joh 8:34-36; Gal 5:13; Pe1 2:16; Pe2 2:19). Unlawful things ruin thousands; "lawful" things (unlawfully used), ten thousands.

— Jamieson-Fausset-Brown Commentary (public domain)