Acts 2:38 and 39 was an answer to a question. An altar call, if you will. Peters sermon began with verse 14 and ends with verse 36.
I've always found it interesting that the Bible says
And they continued stedfastly in the apostles' doctrine and fellowship, and in breaking of bread, and in prayers. Act 2:42 The Apostles Doctrine, as far as we know, consisted of two sermons. (Acts, 1:16-23 and
Acts 2:14-36, 38-39). I'm sure there was other teaching and preaching going on during that period. Wouldn't it have been nice if someone would have written those messages down?
Question: Can we extropolate, from these two sermons, all the teachings we often refer to as the Apostoles Doctrine? (Oneness, Baptism, Holiness, etc.) In other words, can we base Apostolic teachings in their entirety on these two sermons?