"George Müller prayed for two men daily for upwards of sixty years. One of these men was converted shortly before his death, I think at the last service that George Muller held, the other was converted within a year after his death. One of the great needs of the present day is men and women who will not only start out to pray for things, but pray on and on and on until they obtain that which they seek from the Lord." ~ R.A. Torrey

"George Müller, one of the mightiest men of prayer of the present generation, when the hour for prayer came would begin by reading and meditating upon God’s Word until out of the study of the Word a prayer began to form itself in his heart. Thus God Himself was the real author of the prayer, and God answered the prayers which He Himself had inspired." ~ R.A. Torrey

George Müller, to whom reference has already been made, was a mighty man of prayer because he was a mighty giver. What he received from God never stuck to his fingers; he immediately passed it on to others. He was constantly receiving because he was constantly giving. When one thinks of the selfishness of the professing church today, how the orthodox churches of this land do not average $1.00 per year per member for foreign missions, it is no wonder that the church has so little power in prayer. If we would get from God, we must give to others. Perhaps the most wonderful promise in the Bible in regard to God’s supplying our need is Phil. 4:19, “And my God shall fulfill every need of yours according to His riches in glory in Christ Jesus.” ~ R.A. Torrey

"One of the mightiest men of prayer of the last generation was George Mueller of Bristol, England, who in the last sixty years of his life (he lived to be ninety-two or ninety-three) obtained the English equivalent of $7,200,000.00 by prayer. 

But George Mueller never prayed for a thing just because he wanted it, or even just because he felt it was greatly needed for God's work. When it was laid upon George Mueller's heart to pray for anything, he would search the Scriptures to find if there was some promise that covered the case. 

Sometimes he would search the scriptures for days before he presented his petition to God. And then when he found the promise, with his open Bible before him, and his finger upon that promise, he would plead that promise, and so he received what he asked. He always prayed with an open Bible before him." 

- R. A. Torrey on George Müller; "The Power of Prayer," 1924 (P. 81)