If it is possible that what the Apostles wrote later was not consistent with what they preached before, then the Apostles cannot be trusted. Apostolic succession would fall apart for that reason alone.
FK: "My contention is that the conversations appearing in John were "basically" orally and correctly taught leading up to the actual drafting of the text."
That means +John's Greek was flawless (actually better than +Paul's) from the getgo and his theology fully developed. If that's what he was teaching from the beginning, then it is surely strange the Synaptic Gospels don't mention any of it.
Well, then it is also surely strange that none of the whole Bible speaks anything of Mary being sinless. :) The quality of John's Greek doesn't bother me since I have a very different view of God's involvement in the creation of the scriptures. I'm sure John's theology grew, as it does with all of us, but I maintain that his original oral teachings were consistent with his later writings.
The Church is the one that, when tested, formulated correct theology (Trinity), and Christology (two natures, one Person) based on what the Church believed "everywhere and always" but was not necessarily expressed. The other alternative is that all other "churches" were equally "true," and all Gnostic, Docetist, Monophysite, Montanist, Marcionist, Ebionite, etc. theologies were equally "true"."
That's not the only alternative. Your Church could have been wrong on several things, as well as other churches. Perhaps the Church that was closest to being right was stamped out by a more powerful one. We cannot know for sure, but it does not follow that either your Church is 100% correct or all the others are equally correct. My church is closer to being correct than yours is, but that does not mean that mine is 100% right and yours is 100% wrong.
The Apostles did not from the beginning believe one and the same thing. That much is certain. They do not lie when they make that obvious in their writngs. We all grow in faith, and the Apostles were no different in that regard. Their faith was not "downloaded" complete and indexed as St. Pauls seems to claim. GThey did not really have a clear concept of just who Jesus, and their faith was not exactly rock-solid until much later.
I'm sure John's theology grew, as it does with all of us, but I maintain that his original oral teachings were consistent with his later writings
If they were, they are nothing like the teachings of others.
Your Church could have been wrong on several things, as well as other churches. Perhaps the Church that was closest to being right was stamped out by a more powerful one
Then what you believe as far as the Holy Trinity, Christology and the Bible are concerned is posisbly wrong.
Trouble is, there is no record of any other "church." As early as 105 +Ignatius speaks of the "catholic Church." All other "churches" in those days differed from the catholic Church in that their disputed or denied one or more aspects of the Holy Trinity, Christology, and scriptre (e.g. Marcion).