Samuel Logan Brengle (1860–1936) was a commissioner in The Salvation Army and a leading author, teacher and preacher on the doctrine of Holiness. His books include The Soul Winner's Secret, Helps to Holiness and Heart Talks on Holiness. He was an exceptional scholar, and while a number of opportunities were open to him, he felt that his calling was to be a preacher and so following university, he became a circuit preacher for the Methodist church. Later on he was encouraged to study theology and so he enrolled at the Boston Theological Seminary. It was at this seminary that he was exposed to the teaching of holiness, and later claimed the experience for his own life. He was once asked for his secret of holiness to which he replied: "Keep in the will of God, obey Him, seek Him daily, waiting at His gates. Read the Bible regularly. Never neglect secret prayer. Keep testifying to the grace bestowed upon you. Help others."