As a volunteer, I taught English to immigrants for one year. One day a Tibetan Monk walked up to me. He was dressed in his orange robes and everything. He asked me, "Why is America so rich, but so many other countries are so poor?"
I almost answered, "Because we are a Christian nation." But I know Haiti is a Christain nation... and they are as poor as it gets. So I had to tell him, "I don't know!" It bothered me for many years. The best answer i have come up with is, "It is God's will and it serves His purposes for reasons only He knows."