Common wisdom often equates the earliest example of something with the most pure form. Things were best in the “good old days” and we need to get back to those good old days in the present church. But the earliest is not always the best. It is also true ideas develop over time. Sometimes the earliest form is simpler or more pure, but not necessarily better than the more mature forms. While I might be nostalgic for my first computer, I am not really willing to go back to using a Commodore 64.
The argument Acts ought to be normative for church involves the practice of the early Christians, not doctrine. Obviously doctrine develops later with the Pauline letters and later Christians who seriously thought through who Jesus was and what he did on the cross.
In addition, the book of Acts seems to indicate that the earliest form of Christian was far less unified than we sometimes imagine. By Acts 6, there is some division between Hellenistic Jews and the Jews from Judea. There seem to be some Christians who were Pharisees and taught that Gentiles ought to keep the law, so that by Acts 15 a “church council” must be called to deal with this issue.
We can talk about Paul, Peter, and James as leaders of the church, but quite different agendas. Acts 18 there are some people who only knew that John the Baptist had come, not Jesus as the messiah, not had they received the Holy Spirit! Rome appears to have had some form of Christianity before Paul or Peter arrived there, so that Paul is greeted by the brothers when he arrives in Acts 28.
The book of Acts becomes the beginning point of a trajectory from the first moments of the church to present practice. What are practices which “develop” from Acts, through the epistles and through Church history? Is there any danger to clinging too tenaciously to “church tradition”?