"Man, enticed by the Evil One, abused his freedom at the very beginning of history." He succumbed to temptation and did what was evil. He still desires the good, but his nature bears the wound of original sin. He is now inclined to evil and subject to error:
Man is divided in himself. As a result, the whole life of men, both individual and social, shows itself to be a struggle, and a dramatic one, between good and evil, between light and darkness.
Source: Catechism of the Catholic Church (Vatican.va)