“For as many as are led by the Spirit of God, they are the sons of God” (Romans 8:14).
The Apostle Paul is known for his strong stance on morality for Christians, even as he is known to wrestle against the legalism of the Jews (Gal 3). He taught that Believers are free from the Law of Moses (which he also called the Law of Sin and Death (Rom 8:2)), but emphasized that we are now slaves of Christ (to imitate Him in righteousness). He walked a thin line between GRACE and TRUTH, speaking much about our liberty and our chains (1 Cor 7:22).
There is a danger for anyone who walks this thin line of Grace and Truth to slip over to one side on an issue they feel strong about, and to the other on an issue they are weak about, so that they are more gracious to themselves and more judgmental of others. In the wake of liberty, error came into the Church by those who used their liberty as an occasion to the flesh (Gal 5:13). We see that Paul had to chastise the Corinthians strongly for sins of fornication. Perhaps they thought that since they were no longer bound to the Jewish Law, anything goes. Paul had to set them straight.