A Christmas Rumination by Francis W. Porretto:
A good man -- take my word for it -- has succumbed to the Problem of Pain: the inability to believe that a benevolent Deity would have created a universe that permits so much evil and suffering. I had to grapple with that one myself before I could confidently return to faith. It's a nasty one, for one giant reason: the severe difficulty we limited ones have in contemplating the nature of God and the Divine Plan.
The heart of the thing is the nature of free will under the veil of Time. We are temporal creatures. Alone among the living species, we experience the passage of time, in which we sequence the events of our lives and concoct theories about why this happened instead of that. Because our wills are free, we are capable of taking many paths forward from any point in time and circumstance. The scope of our decision making is limited only by our nature.
Our nature is defined by the laws of the universe that gave rise to us. God decreed those laws and made them self-enforcing. But they don't constrain our wills. We are free to choose what ends we will pursue: pleasure or pain; profit or loss; stasis or dynamism; good or evil. Freedom of the will is God's original gift to Mankind: the one that distinguishes us from all the lower orders...and perhaps from some of the higher ones, as well.
A woman at my workplace went to India with her daughter. One day they decided to visit a temple. The level of poverty and misery there made the daughter tear up. She couldn't handle such a scene. She asked her mother, "How can God allow this?" The mother, to my surprise, didn't have any answer. She largely agreed with the idea that suffering means that a good God doesn't exist which basically means God doesn't exist.
I've not believed that. Even, after viewing the horrors of Islam in Pakistan and Saudi Arabia, my belief in a Powerful Architect hasn't diminished. If anything the existence of evil strengthens the basis of His existence for it means that we truly are free -- free to be good or bad, free to be kind or inflict pain.