One other point about the “Bishops and Deacons” argument is that it relies on the assumption that the early Church in Paul’s time had no leadership structures in place whatsoever. I find this highly implausible to the point of absurdity. Sure, they may not have had all the formal procedures and ceremonies and exams and qualifications involved in selecting and ordaining deacons and bishops that we know today, but the disputed letters of Paul don’t describe any of those formal procedures and ceremonies and exams and qualifications but just says that the people in charge were called “bishops” and “deacons”. To suggest that they didn’t even have names for the leadership posts is almost like saying that they didn’t have any leadership structures in place at all, and that sounds very, very far fetched to me. In fact we see some form of leadership structures in place right at the beginning of the Acts of the Apostles and even in some of Jesus’s teachings (e.g. Matthew 16:17-19, 18:15-17).
We could make an analogy by considering the history of the Internet. Most people only first heard of the Internet in the 1990s, after Tim Berners-Lee released the first web browser at the end of 1990. But references to the Internet were knocking around in tech circles long before that. One of the earliest examples was a document that rejoices in the name of RFC 675, which was written as long ago as December 1974 and which describes the communication protocols that the Internet was to use. By Bart Ehrman’s reasoning, that particular document could not have been written any earlier than the 1990s and must be a forgery because the Internet “was a much later development.”