Do not forget that prayer is ordained for the purpose of glorifying the name of God. Therefore, whether you pray for big things or for little things, say to God, "If it will glorify Thy name, then grant my prayer and help me."
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.