“But you were washed, you were sanctified, you were justified” (v11). Paul wanted the Corinthians to live out their new identity as God’s people. Roman society was full of petty legal disputes, but Paul told the believers that their issues (civil, not criminal cases) should be resolved before ever going to court. "All things are lawful for me, but not all things are helpful” (v12). In the same way, their sexual behavior should be entirely different from Roman society, since they belonged to the Lord (v19-20).
“So glorify God in your body” (v20). We are forgiven and accepted into God’s family so that we can fulfill our original purpose – to glorify Him with our lives.