Problem of Evil by Peter Kreeft. The problem of evil is the most serious problem in the world. It is also the one serious objection to the existence of God. No sane person wants hell to exist. If it is intellectually dishonest to disbelieve in evil just because it is shocking and uncomfortable, it is the same with hell.
Reality has hard corners, surprises, and terrible dangers in it.
We desperately need a true road map, not nice feelings, if we are to get home. So does Auschwitz. So does Calvary. The many arguments for the existence of God are like roads, starting from different points but all aiming at the same goal. Insights from Origen Scholarship by Daniel C Hauser.