Over and over again throughout Christian history, mighty men and women of God have singled out one very specific spiritual action as the "Christian secret" to their personal triumph and effectiveness in the kingdom of Heaven. Hudson Taylor, Leonard Ravenhill, A.W. Tozer, D.L. Moody, Oswald Chambers, John Bunyan, C.T. Studd, Amy Carmichael, Ian Thomas, and countless more all point to the very same thing. So, what is it?