Charity
Sometimes suffering makes an important good possible. If God eliminated that suffering, the corresponding good also would be eliminated.
We could say that suffering . . . is present in order to unleash love in the human person, that unselfish gift of one’s "I" on behalf of other people, especially those who suffer. The world of human suffering unceasingly calls for, so to speak, another world: the world of human love; and in a certain sense man owes to suffering that unselfish love that stirs in his heart and actions. (SD 29)
Humility
Suffering can bring us closer to what is good and can draw us away from obstacles to achieving happiness. Pain can prompt rehabilitation, a turning from evil to embrace stronger relationships with others and with God (SD 12). Suffering breaks down that most fundamental of human proclivities: our desire to be God. The atheistic existentialist Jean Paul Sartre wrote: "To be man is to reach toward being God. Or, if you prefer, man fundamentally is the desire to be God." The original sin of Adam and Eve was an attempt to reorder the universe so they could determine what is good and what is evil. This is replicated in every human sin. The sinner orders the universe according to his own will and sets aside the will of God. Suffering is redemptive in part because it reveals to man that he is not God, rendering him more receptive to the divine:
To suffer means to become particularly susceptible, particularly open to the working of the salvific powers of God, offered to humanity in Christ. In him God has confirmed his desire to act especially through suffering, which is man’s weakness and emptying of self, and he wishes to make his power known precisely in this weakness and emptying of self.