Learn How to Pray with Power Charles Finney's ministry rolled like a spiritual shock wave across the American landscape in the nineteenth century. He attributed his effectiveness in large part to prayer. Now his superb insights are condensed and collected in a single book. Principles of Prayer provides a 40-day devotional study for those desiring to pray with power and see results. Each daily reading-through meditation, application, and prayer-will help you grow to Christian maturity. Charles G. Finney, widely acknowledged as one of America's foremost evangelists, was a great man of prayer as well. Over half a million people were converted under his ministry in the 800s.