The Catechism of the Catholic Church speaks of sin as follows:

"Sin is an offence against reason, truth, and right conscience; it is a failure in genuine love for God and neighbour caused by a perverse attachment to certain goods.... It has been defined [by St Augustine] as "an utterance, a deed, or a desire contrary to the eternal law."

"Sin is an offence against God.... Sin sets itself against God's love for us and turns our hearts away from it. Like the first sin, it is disobedience, a revolt against God through the will to become "like gods," knowing and determining good and evil. Sin is thus "love of oneself even to the contempt of God.""