D. L. MOODY (1837-1899) was probably the most well-known and respected evangelist in the late 1800's. He preached to thousands on both sides of the Atlantic, started schools and established what is now Moody Bible Institute. SECRET POWER (or, "The Secret of Success in Christian Life and Work") is Moody's classic work on the need for reliance on the Holy Spirit. He gives a brief survey on the person and work of the Holy Spirit, as well as the necessity for belivers today to seek the Spirit of God for fullness of power.
Moody differentiates between the Spirit being "in" a believer at conversion, and resting "upon" them in power for service. He looks at how the Holy Spirit empowers a believer as well as some of the things that may hinder His work.
A powerful and practical classic that is still very relevant today