This insightful essay, when fully completed, will explore the intricate psychology behind religious experiences across three parts. Currently, two parts are published, with the first delving into the conversion process through six distinct phases The Sense of Sin, Self-surrender, Faith, Joy, the Appearance of Newness, and The Role of the Will. In Part II, we juxtapose Christian doctrines regarding Justification, Faith, the Grace of God, and the Freedom of the Will with the compelling narratives from Part I. Notable stories of conversion from figures such as Samuel H. Hadley, St. Augustine, John Bunyan, John Wesley, Jonathan Edwards, John B. Gough, Colonel James Gardiner, Jeremiah Hallock, and J.O. Peck are discussed, making this a significant publication referenced in numerous works. (Summary by Curt Walton)