Sexual immorality.

Be ye therefore followers of God, as dear children; and walk in love, as Christ also hath loved us, and hath given himself for us an offering and a sacrifice to God for a sweetsmelling savour. ButFORNICATION, and all uncleanness, or covetousness, let it not be once named among you, as becometh saints; neither filthiness, nor foolish talking, nor jesting, which are not convenient: but rather giving of thanks. ( Ephesian 5:1-4 )