With respect to the theory of baptism, the Anti-Gnostic Fathers said that the Spirit is united with the water as it was in the Gnostic mysteries. The Spirit and this was easy especially for Tertullian as a Stoic is so to speak a material force in the water.
This force some physically extinguishes the former sins and gives, physically, the Spirit. Here we have contradictory statements, but these statements were made. It is the famous “materialism” of Tertullian, who thought in these terms. This was very important because it made infant baptism possible. If the water is the saving power, then the child can be saved as much as the adult.
Now it was not without hesitation that Tertullian accepted this doctrine, but Christianity had to accept it in the moment in which one ceased to baptize individuals called out of all paganism, and baptized all nations. Then you cannot exclude the children. But if you include the children, then you must have a completely objective theory, because children are not subjects who can decide. And this is what people of that time saw, and what Luther and the Reformers saw therefore the strong emphasis on baptism in order to make it possible for everybody to participate in it.
The Lord’s Supper is for Irenaeus the physical mediation of immortality; the union of heavenly and Divine elements take place. Participation in it is continuous reincarnation.
Now these ideas are the Roman church, and they are ideas which became extremely inf luential in the long run, and have finally conquered all other ideas. The Catholic church was ready about the year 300, I. e., it needed only a very short time to be brought into fulfillment because all the motives were ready, they were ready in paganism, and paganism couldn’t receive Christianity without these elements.