The advancing centuries witnessed a constant increase of error in the doctrines put forth from Rome.
Even before the establishment of the papacy the teachings of heathen philosophers had received attention and exerted an influence in the church. Many who professed conversion still clung to the tenets of their pagan philosophy, and not only continued its study themselves, but urged it upon others as a means of extending their influence among the heathen.
Serious errors were thus introduced into the Christian faith.
Prominent among these was the belief in man's natural immortality and his consciousness in death. This doctrine laid the foundation upon which Rome established the invocation of saints and the adoration of the Virgin Mary.
From this sprang also the heresy of eternal torment for the finally impenitent, which was early incorporated into the papal faith.¹
Then the way was prepared for the introduction of still another invention of paganism, which Rome named purgatory, and employed to terrify the credulous and superstitious multitudes.
By this heresy is affirmed the existence of a place of torment, in which the souls of such as have not merited eternal damnation are to suffer punishment for their sins, and from which, when freed from impurity, they are admitted to heaven. ²
¹ For a exhibition of Biblical teaching about this subject, see my blog EL DESTINO DEL HOMBRE.
² Purgatory.--Dr. Joseph Faa Di Bruno thus defines purgatory: "Purgatory is a state of suffering after this life, in which those souls are for a time detained, who depart this life after their deadly sins have been remitted as to the stain and guilt, and as to the everlasting pain that was due to them; but who have on account of those sins still some debt of temporal punishment to pay; as also those souls which leave this world guilty only of venial sins."--Catholic Belief (1884 ed.; imprimatur Archbishop of New York), page 196.
See also K. R. Hagenbach, Compendium of the History of Doctrines (T. and T. Clark ed.) vol. 1, pp. 234-237, 405, 408; vol. 2, pp. 135-150, 308, 309; Charles Elliott, Delineation of Roman Catholicism, b. 2, ch. 12; The Catholic Encyclopedia, vol. 12, art. "Purgatory."