jay88, you make an interesting point. Paul was like a russell or rutherford in his interpretation of old testament writings. It is clear in his own writings that people were definitely challenging his position and teaching such as in Galatians. He even went so far as to say that no man had taught but recieved his teaching directly from Christ.
He even said that if anyone accepted another gospel or brought another, they would be accursed. Its kinda like the organization saying that if anyone accepts another teaching not from them it is apostasy and the person will be accursed.
I would recommend reading " Jesus' Words Only or Was Paul the Apostle Jesus Condemns in Revelation 2:2" by Douglas del Tondo. The Pdf is available to be read for free at http://www.jesuswordsonly.com/JWO/freechaptersonline.html. If anyone reads it let us know what you thought. It covers not only biblical but also non-canonical and historical sources to dig into Paul's history and his errors in issues with regards to the jewish Law and with the other apostles, namely the Jerusalem council.
Robert Eisenman has some good reads on this subject as well.
PVT81