63. That the sin of fornication is grievous. In the first Epistle of Paul to the Corinthians: “Every sin whatsoever a man doeth is outside the body; but he who committeth fornication sinneth against his own body. Ye are not your own, for ye are bought with a great price. Glorify and bear the Lord in your body.” 4515 4515     1 Cor. vi. 18–20 .