Dwight L. Moody, the renowned evangelist, believed that the power of the Holy Spirit had been too much overlooked, as though it were not practical.

Moody wrote, "The result is lack of power in testimony and work. If we would work, 'not as one that beats the air,' (I Corinthians 9:26) but to some definite purpose, we must have this power from on high. Without this power, our work will be drudgery. With it, it becomes a joyful task, a refreshing service. May God make this book a blessing to many. This is my prayer."

This version of The Secret Power has been revised into modern English, and includes biographical details on Dwight Moody's life.

Dwight L. Moody was a highly acclaimed late 19th century evangelist. He founded the Moody Bible Institute of Chicago and the Bible Institute of Colportage Association, now Moody Press. He survived the turbulence of the Civil War and the Great Chicago Fire. He and his wife, Emma, had two children.