In contrast with Romans 7:20:
But if I am doing the very thing I do not want, I am no longer the one doing it, but sin which dwells in me.
Genesis 4:7: states
7“If you do well, will not your countenance be lifted up? And if you do not do well, sin is crouching at the door; and its desire is for you, but you must master it.”
are these Scriptures contradictory, and how does mainline Christianity interpret each?