Suffering is both a reminder and a guide. It stimulates us better to adapt ourselves to our environmental conditions, and thus leads the way to self improvement. In every suffering one can find a meaning and a wisdom. But it is not always easy to find the secret of that wisdom. It is sometimes only when all our suffering has passed that we become aware of its usefulness. What man considers to be evil turns often to be a cause of infinite blessings. And this is due to his desire to know more than he can. God’s wisdom is, indeed, inscrutable to us all, and it is no use pushing too far trying to discover that which shall always remain a mystery to our mind.
(Shoghi Effendi, Unfolding Destiny, p. 434)