The proper theological response to the problem of reconciling human suffering with the Christian belief in a God of infinite wisdom, power, and goodness is not to try to solve the unsolvable, but to preserve the mystery of God. The concept ‘mystery’ as attributed to God signifies intelligibility — inexhaustible intelligibility — not contradiction. Mystery suggests the range and limits of a human being's knowledge of God. We cannot know why God permits suffering in this particular instance or the character of God's response to someone in the throes of suffering. We can know in a general way the necessary conditions of the possibility for the realization of God's purpose because we know the purpose of God's activity through revelation. This paper argues that if God created the universe so that creatures could share in the fullness of God's life, God could not have achieved God's purpose without any human suffering. This argument upholds the inexhaustible intelligibility of God's activity and thus preserves the mystery of God, for if God could have achieved God's purpose without any suffering, yet willed the suffering of creatures, then the eternal plan of providence and the actual unfolding of salvation history would be arbitrary and irrational.