The prayer that prevails with God is the prayer into which we throw our whole heart, the prayer of intense earnestness; and it is the Holy Spirit who inspires us to that intense earnestness in prayer. Oh, how cold and formal we are in many of our prayers. How little intense longing there is in our souls to obtain the thing that we ask. We pray even for the salvation of the lost with much indifference, though we ought to realize that if our prayers are not heard they are going to spend eternity in hell. But men and women whose prayer life is under the control of the Holy Spirit, pray with intense earnestness; they cry mightily to God; there is a great burden of prayer in their hearts; they pray sometimes with groanings which cannot be uttered.
– RA Torrey –