I. Prayer is founded on knowledge. Before we can speak to God we must know God. "How shall they call," the Apostle asks, "on Him in whom they have not believed?" Even the prayer of the heathen, so far as it is prayer, rests upon knowledge. (1) Let the man who would pray aright begin by studying his Bible. Let him first acquaint himself with God, and then speak to Him. The Word of God tells us in a thousand manners what He is in Himself, and what He is in His doings towards the children of men. He who would ask of God must first know God, and he must carry that knowledge into the asking. He must never ask of God anything which it would contradict the character of God to grant. The prayer which presupposes knowledge must also be a prayer which recognizes and remembers it. (3) In Christ, God is revealed; and upon the knowledge of Christ, therefore, is prayer to God founded. The words with which Christian supplication is always winged and speeded through Jesus Christ our Lordare a perpetual memento of that first condition of prayer, that it be founded on the true knowledge of God, and carry that knowledge with it to the mercy-seat of God's Presence.
II. Prayer founded on knowledge is prompted by desire. The man who asks of God must desire too.
III. Prayer, founded on knowledge and prompted by desire, must be bounded by promise. The promise of which we speak is no single, separate utterance; no number, no multitude, of bare, literal engagements, which must be found somewhere in the bond, and then rehearsed by page and clause, as the justification of the particular demand. The promise of God, like the revelation of God, like the counsel of God, like the character of God, is at once ample to magnificence and simple even to unity. There is no limit to prayer but promise, and no limit to promise but the soul's good.
C. J. Vaughan, Voices of the Prophets,p. 158.