'Immorality' in the Bible

It is actually reported that there is sexual immorality among you, and such sexual immorality as is not even named among the Gentiles, that one has his father's wife.

"Foods for the belly, and the belly for foods," but God will bring to nothing both it and them. But the body is not for sexual immorality, but for the Lord; and the Lord for the body.

Flee sexual immorality! "Every sin that a man does is outside the body," but he who commits sexual immorality sins against his own body.

Neither let us commit sexual immorality, as some of them committed, and in one day twenty-three thousand fell.