Well, your friend was off by a century, and I wouldn't use the term "corrupted." The Catholic Church solidified a biblical canon in the late 4th
century, but the books they included in that canon were already used by the majority of Christians in existence at that time. I think the canon was
solidified because they wanted certain gnostic texts to be kept from being read - this is not really a conspiracy though, as I imagine the early
church Fathers would tell you the exact same reason fro solidifying the canon. It certainly wasn't done in secret.