Quoting from "Living the life God has Planned":
George Mueller was burdened to encourage people to experience the faithfullness of God. He founded an orphanage not only because he cared about the needy children but because he wanted God's people to see that He is faithful and will answer prayer. He saw older people living in fear of whether they would be forsaken by God. He saw people operating unethically in their careers because the feared that they could not compete if they lived honestly in the business world. To honor God's faithfulness was his objective in starting an orphange and making his needs known only to God. In his lifetime he recorded more than fifty thousand prayer, and many of these are found in the book Answers to Prayer
Quoting from http://en.wikipedia.org/wiki/George_M%C3%BCller :
Müller prayed about everything and expected each prayer to be answered.
Once, whilst crossing the Atlantic, his ship ran into thick fog. He explained to the captain that he needed to be in Quebec by the following afternoon, but the captain said that he was slowing the ship down for safety and Müller's appointment would have to be missed. Müller asked to use the chartroom to pray for the lifting of the fog. The captain followed him down, claiming it would be a waste of time. After Müller prayed, the captain started to pray, but Müller stopped him; partly because of the captain's unbelief, but mainly because he believed the prayer had already been answered. When the two men went back to the bridge, they found the fog had lifted.
The captain became a Christian shortly afterwards.
Müller's faith in God strengthened day by day and he spent HOURS in daily prayer and Bible reading.