Take a look at this powerful animation that explores the nagging question, "If God is all-good and all-powerful, why is there evil in the world?"
"Down through the centuries and generations it has been seen that in suffering there is concealed a particular power that draws a person interiorly close to Christ, a special grace. To this grace many saints, such as Saint Francis of Assisi, Saint Ignatius of Loyola and others, owe their profound conversion. A result of such a conversion is not only that the individual discovers the salvific meaning of suffering but above all that he becomes a completely new person. He discovers a new dimension, as it were, of his entire life and vocation.
"This discovery is a particular confirmation of the spiritual greatness which in man surpasses the body in a way that is completely beyond compare. When this body is gravely ill, totally incapacitated, and the person is almost incapable of living and acting, all the more do interior maturity and spiritual greatness become evident, constituting a touching lesson to those who are healthy and normal."
SALVIFICI DOLORIS - Letter of Pope John Paul II on the Christian Meaning of Human Suffering, 1984