psycholatry

Then come into being idolatry, psycholatry, henotheism. Idolotry is the worship of an image only, of a symbol of something else. Psycholatry is the worship, the great reverence paid to the spirit of the departed.

1904, M.C. Alasingaperumal, The Brahmavâdin, volume 9 (Hinduism), Zs8aAAAAYAAJ, page 510

When, moreover, we call to mind that the spirits of the dead, who at this season leave their graves and hold high revel with the fairies, seem really indistinguishable from the latter, the conclusion irresistibly forces itself upon us, that in the cult paid to the fairy race we have a survival of the worship of departed souls, or psycholatry as it is sometimes called, which is, so far as we know, one of the oldest religions in the world, even if it be not, as many high authorities maintain, the primitive religion of mankind.

1890, W.H. Allen, The National Review, volume 14 (Great Britain), Qik_AQAAMAAJ, page 761

Another form of religion called psycholatry holds in reverence the spirit of the departed.

1889, A. Tompkins, The Universalist Quarterly and General Review, volumes 46–47 (Universalism), c2pJAQAAMAAJ