Augustine of Hippo

Though his carnal desires still exist, the man who is renewed by grace by not giving in to sin does not serve them. With his mind he serves the law of God, even though with his flesh he serves the law of sin. Paul calls the law of sin the mortal condition which stems from the transgression of Adam, because of which we are born mortal. It is because the flesh has fallen that the lusts of the flesh entice us.