If you haven't noticed the detailed discussion on Orthodoxy a couple of posts back, then go check it out. Roy spent A LOT of time answering one question that I thought would be nice to just copy it back here and open it up to more discussion. It's kind of lengthy, but it's on the very good question of what "orthodox" Christianity looked like early on and I think can impact how we view Christianity today.
For those of you who don't know Roy personally, he is currently a Ph.D. student at Baylor and a great guy. He also is somewhat like me and has lots of opinions. Fortunately, we mostly agree. That being said, here's the contents of his last post which was in response to a question concerning what the debate was in the 2-4th century...
ROY:
The second-fourth century is my secondary area (my major is New Testament) and within that my focus has been on second century "heresies," particularly Montanism. The problem with that much specialization is it tends to obscure the forest by looking at the bark on one tree.The basic question is whether or not there was such a thing as pre-Nicene orthodoxy (remembering that it took some time for Nicea to be accepted as the standard). The answers range from no to a qualified yes to a definite yes. As you might suspect, many, especially since Walter Bauer's _Orthodoxy and Heresy in Earliest Christianity_ answer no. My take on Bauer is that he is not only quite difficult to read, but he is rather selective in his evidence, rarely taking documents as a whole.
This is quick and unfair to Bauer, but if you want some heavy reading, you'll see what I mean, I think. That being said, I can't give an unqualified yes either. The best I can do here is give another example like the previous one on the nature of Christ, though I will admit that in several senses this is not as strong an argument. Notice that once again, I pick an example with which I am familar and argue from the specific to the general. By the 4th-5th century, Montanism, which held that prophetic utterances continued in the post-apostolic period, was largely condemned as a movement (obviously not in a councilar statement, since this is a little too early for that).
Despite the later condemnations, which were vivid and strong--Justinian ordered the destruction of a Montanist shrine to be carried out by John of Ephesos to make the position clear in his See in 550. Most mark this as the end of Montanism--there was quite a bit of uncertainty in the late 2nd-early 3rd century as to what to do with Montanism. As you might expect, our evidence is mostly negative--4-5 century Christians tended to destroy works they saw as heretical--but in the case of Montanism we have 3 possibly early witnesses. The first two, an Anonymous source used by Eusebius, and what is possibly an early source in Epiphanius, are decidedly hostile, using strong words of condemnation.
The last, however, is from a proponent of Montanism (he calls it the New Prophecy)--Tertullian. Though we see Montanism being strongly condemned (and losing in the end), it apparently existed and even flourished for at least a time and its proponents were considered orthodox. We have a considerable amount of archaelogical evidence for Montanism in Turkey, the evidence of Tertullian that it was in Carthage, the evidence of Tertullian that the bishop of Rome intended to grant it favor but changed his mind, and evidence that a movement like it existed in France.Thus (if you've made it this far ), we have a movement that brought into question the nature of authority, revelation and prophecy and it took the church perhaps as long as 100 years to deal with it and our evidence suggests that, like other issues, including Arianism (the focus of Nicea), it was individual Sees that established orthodoxy in their jurisdiction and sometimes orthodoxy would change with the next bishop (we have no evidence of this changing with Montanism, though--I made the leap due to space/time considerations).
So, the basic point is that theology was developing, especially in 2-4 century. The Christological developments are the most dramatic instances, at least to me, since you actually see the understanding change over time, in ways that I think are much more important than what eventually brought about the Great Schism. It just seems difficult to pin down the Church of this time span with a particular viewpoint regarding most doctrinal issues. This is true later as well, even in the East (iconoclasts, for example), but seems to be more pronounced in this early period. Keep in mind that this was way too brief, way too selective and quite slanted simply due to the format in which this is taking place. I can point to more detailed resources if anyone is interested. If you're interested in Montanism, I have a paper on their teachings (not their history), but due to time limitations I was under, I didn't translate any of the Greek, Latin or French in it, which can make it hard to follow. I may do that for my own purposes this Summer, but really, who cares? There is also a great website on Tertullian: tertullian.org.If you made it this far, you're either really interested, really bored or masochistic