It is reported that someone amongst you is sleeping with his father’s wife. This is highly immoral–punish him! Do not eat or associate with fellow believers who are greedy, idolatrous, revilers, or drunkards. Do not take each other to court to be judged by unbelievers–it is better to be wronged. Do not go to prostitutes, for you will be joined to her as one body; fornication is a sin against the body. It is better to not get married, because the unmarried can fully devote themselves to God while the married have to care for their spouses. But those who cannot control their passions should get married as a second-best option–it is better to marry than to be aflame with passion.
The circumcised should not try to hide their circumcision, the uncircumcised should not get circumcised, and slaves should not seek to be free. With regard to eating food sacrificed to idols, there is nothing inherently wrong with it for those who are strong in faith. However, everyone should refrain from it to avoid setting a bad example for those weak in faith.
Commentary: Why does Paul advise the unmarried against getting married (7:25), the uncircumcised against getting circumcised (7:19), and the slaves against trying to be free (7:21)? Paul tells us:
I think that, in view of the impending crisis, it is well for you to remain as you are. […] I mean, brothers and sisters, the appointed time has grown short; from now on, let even those who have wives be as though they had none, and those who mourn as though they were not mourning, and those who rejoice as though they were not rejoicing, and those who buy as though they had no possessions, and those who deal with the world as though they had no dealings with it. For the present form of this world is passing away. (7:26-31)
To Paul, the end of the world was near. The “impending crisis” is not anything that would happen on Earth; it refers to the tribulations before the second coming of Jesus, when “the present form of this world” would pass away. It doesn’t matter that much, therefore, whether one gets married or circumcised or freed from slavery; no matter what, the end times are near.