It's the most important subject in Christianity. It reveals who God is, how God works, how we mature as followers of Jesus, and how we are to conduct ourselves in this sinful world. The subject is suffering. To explore it biblically and inspirationally is to identify the basic elements of a responsible Christian theology that's more than a set of pious abstractions. This subject forces us close to where we hurt, doubt, believe, and relate to our neighbors.
God suffers, Jesus cries. The tears of God are the deepest meaning of our history. God's "problem" is not that God is not able to do certain things, but that God loves. The cross of Jesus was in God's heart before it appeared on Golgatha. The pain of God is the healing of humanity. The cross, the worst of human doing and the best of divine revelation, clarifies that we must die to really live. We must share in the sufferings of Jesus.