Start with high-confidence psychology of religion books, then narrow by subgenre or adjacent topics.
Stages of Faith
James W. Fowler
Soul Making
Alan W. Jones
The Evolution of God
Robert Wright
Shamanism
Manvir Singh
The Basic Writings of C. G. Jung
C.G. Jung, Violet Staub. De Laszlo
Ego and Archetype
Edward F. Edinger
The Great Within
Han F. de Wit
The Varieties of Religious Experience
William James
Science and Spiritual Practices
Rupert Sheldrake
Varieties of Religious Experience: a Study in Human Nature
