Penance.
The pagan theory of baptismal regeneration created a necessity for the doctrine of penance. Under the idea that baptism removed all sins up to the time of the ceremony, something was necessary to atone for sins committed after baptism. Dr. Schaff describes the origin of penance as follows:
“The effect of baptism, however, was thought to extend only to sins committed before receiving it. Hence the frequent postponement of the sacrament, which Tertullian very earnestly recommends, though he censures it when accompanied with moral levity and presumption. Many, like Constantine the Great, put it off to the bed of sickness and of death. They preferred the risk of dying unbaptized to that of forfeiting forever the baptismal grace. Death-bed baptisms were then what death-bed repentances are now.
“But then the question arose, how the forgiveness of sins committed after baptism could be obtained? This is the starting-point of the Roman doctrine of the sacrament of penance. Tertullian and Cyprian were the first to suggest that satisfaction must be made for such sins by self-imposed penitential exercises and good works, such as prayers and alms-giving. Tertullian held seven gross sins, which he denoted mortal sins, to be unpardonable after baptism, and to be left to the uncovenanted mercies of God; but the Catholic Church took a milder view, and even received back the adulterers and apostates on their public repentance.”[244]
More need not be said. The reader will readily see the connection between these two elements of paganism; he will also see the deeply corrupting effect of them both.