He says next, false doctrines such as sacramentalism crept into the church very early in its history. Apostasy arose early in the church, and it is impossible for us to know how far-reaching that apostasy was. However, already in A.D. 150, about 50 years after the death of the last of the apostles, there are indications in the writings of Irenaeus that he believed in the saving merits of the sacraments of baptism and communion. This belief became more common as time went on until by A.D.
200, Tertullian took baptismal regeneration for granted. And again, not knocking this article because I have heard that over and over and over and over again. Now, apostasy, he says that they fell into apostasy. I just grabbed a dictionary definition. Apostasy, a total desertion of or departure from one's religion, political party, etc.