The psychology of religion addresses religiosity from a psychological viewpoint. In the Introduction section, the definition, history, and significance of the psychology of religion are described and William James' biography, works, ideological foundations, and methodology are then presented.

Nature of religion and religiosity, origin of religion and religiosity, faith analysis, religious experiences description and explanation, and consequences of religiosity are included in the five chapters of this book, which deals with the underlying foundations of the psychology of religion from James's view. Furthermore, the book reports, analyzes, and criticizes William James' views.

Some topics discussed in this book are listed below: Terminology of religion; definition of religion and religious life; various theories on the origin of religiosity; significance of semi-conscious mind and subthreshold zones in the origin of religion; the will to believe theory in faith analysis; nature, types, and an explanation of religious experience; Judging James and Stace’ views regarding the indescribability of religious experience; mystical ladder from James’ view; backgrounds and factors affecting religious experience; the effect of psychotropic drugs on religious experience; and consequences of religiosity in spiritual, moral, epistemic, emotional, health, and personality coherence dimensions.

According to William James, "Ideally, no one can precede the haughtiness of the saints. The highest flights of charity, devotion, trust, patience, bravery to which the wings of human nature have spread themselves have been flown for religious ideals….”