" The root of an unmortified course is the digestion of sin without bitterness in the heart. When a man hath confirmed his imagination to such an apprehension of grace and mercy as to be able, without bitterness, to swallow and digest daily sins, that man is at the very brink of turning the grace of God into lasciviousness, and being hardened by the deceitfulness of sin. "

― John Owen , Mortification of Sin