James then proceeds in the rest of the lectures to give multitudes of examples demonstrating the mainly positive effects of religious experiences. He writes chapters on the reality of the unseen, conversion, saintliness, mysticism, philosophy and happiness. These treatments remain classics, along with his discussions of individual differences in religious temperaments, such as the healthy-minded and sick souls.
These arguments in defense of religion by James were liberating for me as a convert to Roman Catholicism. My religious mother had been afflicted by schizophrenia and in my aggressively secular family there lurked the suspicion that my ardent religious enthusiasms were signs of pathological tendencies. Yet my faith could meet James' threefold criteria of validity. I was morally helped, intellectually strengthened and joyfully blessed -- for all the long productive life to come.
James served as a sophisticated defender of the faith in atheistic academic milieus encountered. There, too, religious fervor and commitments also carried the odor of craziness. Indeed, James was quite ready to propose that a more sensitive and even neurotic temperament might be more receptive to valid religious truths than more a stolid, unimaginative nature.
https://www.ncronline.org/blogs/ncr-today/william-james-defense-faith-was-liberating