Prayer is a fine, delicate instrument. To use it right is a great art, a holy art. There is perhaps no greater art than the art of prayer. Yet the least gifted, the uneducated and the poor can cultivate the holy art of prayer.
God alone fully understands what each one of us needs; we make mistakes continually and pray for things which would be harmful to us if we received them. Afterwards we see our mistakes and realize that God is good and wise in not giving us these things, even though we plead ever so earnestly for them.