Where can I find personal recordings/letters of early disciples? Do any such documents exist?

We all know the recordings of the Apostles in the Bible. I am also hoping to find any more of such recordings from Jesus' followers back in the days of Acts and in the early established churches. I wonder how these people talked about all the theology issues we talk about today and their personal views on these things, like we often do in this age of the Internet. 

Clarify • Share • Report • Asked November 17 2016 • Marko SImurina