@Zuma, I think you are making some assumptions about Jesus’ original followers.
The fact of the matter is that we don’t know much about Jesus’ original cult. The gospels, as you noted, were written decades after Jesus died (though 2nd cent. a.d. sounds pretty late for even John…)
This means that the earliest “Christian” documents we have are from Paul. Contrary to what you indicated, Paul’s “Christology” (the idea that Jesus was divine) was quite developed even in his earliest letters. Jesus’ divinity is basically central to Paul’s theology.
I don’t think Paul is accurate. He’s admitted he never met Jesus; his letters mention absolutely nothing about Jesus’ life or even his moral teachings. They basically co-opt Jesus into the role of Osiris or similar deities in mystery religions popular at the time. I think it’s pretty clear that Paul is basically a charlatan trying to co-opt Jesus’ original cult.
But it does leave the nature of the original cult basically a mystery. We know that Paul’s faction wasn’t the only one of early christians. Other groups would go on to form the more-gnosticy Docetics (they believed Jesus was a pure spirit and had no body) and the more Jewish-flavored Christians that Paul was bitching about in his letter to the Galatians. The earliest letter from Paul is generally dated around 50 A.D. which is supposedly two decades after Jesus was around.
So this basically leaves the gospels, mostly the four in the new testament because others appear later. The exception to the noncanonicals being later is Thomas, which seems to have a lot in common with the “sayings” parts of the syncretic (Mark, Matthew, and Luke) gospels. So this gives weight to the idea that maybe the four gospels were composed of circulating, earlier sources, like collections of Jesus’ “wise sayings.” Also, the author/editors of Matthew and Luke both clearly had copies of Mark (because they both contain most of Mark verbatim), so Mark must be the earliest.
Scholars divide up the gospels based on their styles and presume that they are edited complilations of earlier works (including “Q,” which isn’t actually a physical document but rather, simply, “all of the parts that are the same in Matthew and Luke, but aren’t in Mark).
Which is to say, scholars have tried to piece together “Jesus sayings” that might be earlier than the gospels, or even Paul. And in these sayings traditions—which, possibly, maybe could reflect something Jesus’ original cult believed, the only thing that agrees across all the sources is… Jesus doesn’t like divorce.
Man, I can’t believe I wrote all that. TL;DR: saying a “Christian” is someone who follows Jesus’ so-called “original” teachings is misleading because we really have no idea what those are.