The rite thus settled being a conditio sine qua non of Church membership and spiritual life, it became the basis of the temporal power of the Church. Without it there was no "religion"; and as the communicant in order to retain his rights must make confession to the priest at least once a year, the hold of the Church on the people was universal. Any one rejecting its authority could be excommunicated; and excommunication meant the cessation of all the offices of social life, each man being forced by fear for himself to stand aloof from the one condemned. The obligation to confess, in turn, was an evolution from the primitive practice of voluntary public confession of sin before the Church. When that went out of fashion, private confession to the priest took its place; and when the public reading of such confessions by the priest gave offence, Leo the Great directed that they should be regarded as secret. What was thus made for criminals an easy means to absolution became at length an obligation for all. In the East, indeed, it seems to have reached that stage in the fifth century, when a scandal caused the rule to be given up, leaving to the Western Church its full exploitation. Sacerdotal confession, thus instituted, was one more hint from the book of paganism, sagaciously developed. In the ancient Greek mysteries, priests had unobtrusively traded on the principle that the initiate must be pure, first inviting confession and then putting a scale of prices on ceremonial absolution; but in the pagan world the system had never gone far. It was left to Roman Christianity to made it coextensive with the Church, and thus to create a species of social and economic power over mankind which no other "civilized" religion ever attained.
But yet a third hold over fear and faith was wrought by the priesthood. Even as the priestly saying of Masses, bought at a price, was needed to keep the Christian safe in life, so the buying of Masses could hasten the release of his soul from purgatory after death. Purgatory was, to begin with, yet another pagan tenet, which in the first five centuries was regarded by the Church as heretical, though the text about "the spirits in prison" (1 Peter iii, 19; cp. 1 Cor. v, 5) gave colour to it, and Origen had entertained it. In all the writings of Ambrose it is not mentioned; Augustine treats it as dubious in despite of the authority of Origen; and the Eastern Church has never accepted the tenet. But in the writings of Gregory the Great it is treated as an established principle, with the economic corollary that he who would save himself or his kindred from prolonged pains in purgatory must lay out money on atoning Masses. Thus the whole cycle of real and supposed human experience was under the Church's sway, and at every stage on the course the pilgrim paid toll. The episodes of birth, marriage, and death were alike occasions for sacraments, each a source of clerical revenue; the fruits of the earth paid their annual tithe; and beyond death itself the Church sold privilege in the realm of shadows, winning by that traffic, perhaps, most wealth of all.