Incredible book. Incredible. If you're a Christ-follower it is profoundly challenging in most every area of faith and life. If you're not, the author would encourage you to read it anyway, as many people came to faith in Jesus Christ as a result of reading about Mueller's faith in a prayer-hearing God and seeing God's faithfulness to provide for the work Mueller felt led by God's Spirit to do. I had heard vaguely of Mueller's work (wasn't he the guy that never asked for help and just prayed for food for the orphans and it came?), but I had no idea of the scope and monstrous size of it (2,000 orphans were being fed, clothed, schooled, discipled, and housed at the time of his death, along with several other large evangelistic arms of the ministry without ever even hinting at the needs at hand. Prayer was his only means of provision, to prove that God is faithful.) The author was a well-known and respected pastor himself in that day and a personal friend of Muellers. His faith, insight, and theology play heavily into how well the story is told. It's not just "and then he did this and that," it's "then he did this because he believed X about God and Y about His Word." I read parts of the book twice and plan to read the whole thing again in the next year, it's that good and that different from our culture, how we view God, his word, personal holiness, prayer, taking up our cross, and laying down ourselves for whatever He calls us to.