When we go to our meeting with God, we should go like a patient to his doctor, first to be thoroughly examined and afterwards to be treated for our ailment. Then something will happen when you pray.
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.