I still feel the need to clarify, at least for myself, a response to the query as to why, if we're all Christians anyway, anyone would need to become Orthodox, even if Orthodoxy is the "fullest expression of Christianity." The easy answer is to fall back into the so-called "ortho-fundamentalist" response and simply state that no one outside the Orthodox Church is, strictly speaking, Christian. But I have yet to see that that answer itself is actually an Orthodox answer. On the other hand, the "God will save us by our own individual lights" response is somehow less than satisfying as well because it so easily plays into the pluralistic relativism of our modern Christian culture (which itself just mirrors the secular culture).
It would be much more satisfying to go toe-to-toe in respectful debate with the former conservative church of Christ preacher I once knew each of us defending the thesis that ours was the only true Church. At least there we would have clear markers agreed upon in advance. But in the end it would be wholly artificial and academic. And though in this dialogue we both would clearly communicate with one another--thus making it a successful dialogue--neither of us would likely move from our own positions.
I still don't know if I've lit on a way of expressing why becoming Orthodox is such a fundamental necessity, nor whether my way of expressing that reality will be either persuasive or clarifying. But I'll give it a shot.
The best way I can think of to express it is this: Orthodoxy is all of one cloth. You cannot become convinced of Orthodox beliefs and not also take on all of the life that Orthodoxy gives and obligates one to in those beliefs. This was exemplified for me in a response by one of my professors to my biography of Blessed Hieromonk Seraphim Rose that I happened to have on my desk in my office when the professor stopped by. He expressed bewilderment as to why someone who wanted to become Orthodox (and he claimed to know a little about Orthodoxy) would take on a new name, grow a beard and become a monk. Wouldn't it be much more simple, and authentic, if one simply took on the beliefs and that was that? Why the "dressing