Thanks for the link. I read the 14 Canons and it was very interesting. I guess there is no doubt what the purpose was there. :) The only thing is that while it said that the Baptisms of John the Baptist were different than what the Church does today, it does not say what they actually were. I'm sure that JTB baptized hundreds or thousands of people, but in Catholicism, what for? None of those Baptisms could have incorporated the work of Christ on the cross because it hadn't happened yet. How could anyone's sins be remitted at the time?
John the Baptist was the last of the Old Testament prophets and his teaching and his baptism prepared the way for Christ and Christian Baptism in the same way in which also Isaiah, for example, prepared it, even though in the case of John the Baptist the prophecy was very immediate. Those who repented of their sin following John's call formed, we assume, the body of the first Christian converts after the Resurrection and the birth of the Church.