The way George Muller prayed impressed me very much. He was a man of prayer. One of the way he prayed was by claiming God's promises. Whenever he had a prayer request, he would search for a promise in the Bible that fit that need. Next he would meditate on the scripture. According to Wilkipedia, Christian meditation is a form of prayer in which a structured attempt is made to get in touch with and deliberately reflect upon the revelations of God. Then he will plead for that promise before God. He didn't stop praying for anyone or anything until he got his request. He was fully convinced that God would answer his prayers. In his life, there was no plan B. 2 Corinthians 1:20 For all the promises of God in him are yea, and in him Amen, unto the glory of God by us. Psalm 81:10 open thy mouth wide, and I will fill it.