The capacity to feel pain is a survival mechanism that functions to initiate avoidance of whatever it is causing it. It creates learning and anticipation of negative experience via both consciously recognized and unconsciously triggered reactions to past situations that resemble it. These responses can become habituated between people who have history.
Because pain can become associated with patterns and the human brain has a profound capacity to perceive them, it can become associated with words and then ideas. This gives rise to the notion of good and evil, pleasurable and painful, and thus become ready tools for psychological manipulation. Conform or suffer. Once what is can be made a threat, truth flies out the window. In order not to experience pain a person will flea from any truth that could evoke pain, including the truth that we do not permit ourselves to know our past pain so we don't feel it. This is why we say the truth hurts. The truth doesn't hurt. We hurt and that is the truth we don't want to feel.
This is why those who suffer, who have pain they can't help feeling, those who are driven to know why they suffer are the only ones who can ever truly get free of it.
Freedom from the feeling that one is worthlessly evil requires the death of the notion of evil and that requires, also, the death of all we were taught is sacred.
This is the reason, of course, that the Christian Religion is sacred because it tells us that we have been forgiven of our sins. For some, their faith in the love of God for them becomes their love of Him and all that he is. It's the same for Islam also because if everything that happens happens by the will of God there can't actually be any evil. In psychology, the roots of the origin of pain can be consciously relived and one can consciously remember and see though as an adult far removed from the original trauma, the lies one was forced to believe. To grieve is to heal and the truth is that we have suppressed our grief. We have been told the lie that grief is self pity, just another avoidance devise.