2. The second trait of prevailing prayer is that it aims at a mark, and knows what it is after. When we enter a store or shop we ask the salesman to hand us the particular article we want. There is an enormous amount of pointless, prayerless praying done in our devotional meetings; it begins with nothing and ends nowhere. The model prayers mentioned in the Bible were short and right to the mark. "God be merciful to me a sinner!" "Lord, save me!" cries sinking Peter. "Come down, ere my child die!" exclaims the heart-stricken nobleman. Old Rowland Hill used to say, "I like short, ejaculatory prayer; it reaches heaven before the devil can get a shot at it." 3. In the next place, the prayer that has power with God must be a _prepaid_ prayer. If we expect a letter to reach its destination we put a stamp on it; otherwise it goes to the Dead-letter Office. There is what may be called a Dead-prayer Office, and thousands of well-worded petitions get buried up there. All of God's promises have their conditions; we must comply with those conditions, or we cannot expect the blessings coupled with the promises. No farmer is such an idiot as to look for a crop of wheat unless he has ploughed and sowed his fields. In prayer, we must first be sure that we are doing our part if we expect God to do His part. There is a legitimate sense in which every Christian should do his utmost for the answering of his own prayers. When a certain venerable minister was called on to pray in a missionary convention he first fumbled in his pocket, and when he had tossed the coin into the plate he said, "I cannot pray until I have given something." He prepaid his prayer. For the Churches in these days to pray, "Thy kingdom come," and then spend more money on jewellery and cigars than in the enterprise of Foreign Missions, looks almost like a solemn farce. God has no blessings for stingy pockets. When I hear requests for prayer for the conversion of a son or daughter, I say to myself, How much is that parent doing to win that child for Christ? The godly wife who makes her daily life attractive to her husband has a right to ask God for the conversion of that husband; she is co-operating with the Holy Spirit, and prepaying her heart's request. God never defaults; but He requires that we prove our faith by our works, and that we never ask for a blessing that we are not ready to labour for, and to make any sacrifice to secure the blessing which our souls desire.