To answer the question from a Christian perspective.... "Why does God allow suffering"
There must be some inherent value to suffering that we can't see or understand from our current perspective. Proof of this (from the Christian world view) is that God himself through his son choose to suffer. If God chooses to suffer there must be some degree of value to it.
If God during his mortal existence choose to suffer... who are we to think we can avoid suffering?
God is not asking anything of us he didn't already choose for himself.