This is long. Sorry.
Is there a great deal of diversity among Protestants? Of course there is but we should ask ourselves does man have the right to come to a relationship with His Creator in the manner which he deems appropriate by the gospel? My answer is a very loud and clear 'yes' for...It is for freedom that Christ has set us free. Stand firm, then, and do not let yourselves be burdened again by a yoke of slavery.
Well, that certainly is one way to interpret that verse, and indeed the way I interpreted it for many years. I would ask this, however: Is the picture one sees of the first Christians--the ones converted by the apostles and the direct spiritual (and often biological) descendents of those converts--a picture of a "live and let live" mentality characterized by individualized worship style and differences in doctrine as seen in much of Protestantism? Or is it more communal, with set worship and set authority for doctrine, as seen in the (little c) catholic traditions? This, I know, does go outside the Bible, but since it is the way in which said Scriptures were immediately received by all those who came in contact with the apostles, it demands our attention. If St. Paul were truly saying that we had the "right" to do what you're proposing (yet the very concept of individual "rights" didn't come along until enlightenment-era Europe), why would every apostolic community, from the get-go, be incredibly similar in worship and quite particular about being uniform in doctrine?
Remember, Unity in Essentials, Liberty in Non-Essentials and in all this Love.
Absolutely! Yet who decides what "essentials" and "non-essentials" are? ISTM that Protestants who subscribe to the idea that there's one invisible Church (in spite of doctrinal differences) have to make a lot of stuff "non-essential" to still be in some form of unity. We would say baptism is an essential (many Protestants say this, too, btw), that one receives grace to save his soul from it. We would say the Eucharist is an essential; that we cannot have life without eating the Body and drinking the Blood of Christ. We would say another essential is the belief that salvation is an ongoing, life-long process, that we are
being saved rather than
having already been saved. Protestants also disagree on whether or not baptism of the Holy Spirit, speaking in tongues, infant baptism, confession of faith at a known point in time, believers baptism only, communion as more than a symbol, and other things are "essential" or "non-essential." The two categories are pretty arbitrary, depending only on what group you happen to belong to. It is a nice idea, don't get me wrong, but it's meant to deal with one particular communion. In the case of St. Augustine, who is traditionally seen as the author of the phrase, it was the universal Church, w/out denominations, and so "essentials" and "non-essentials" were already ecclesiastically decided.
I get, though, that you say that several guiding principles are what are labeled "essential" in Protestantism, yet not all Protestant groups could subscribe to these...and, as I'll be attempting to show, the Orthodox might not be as antagonistic towards all these points as you might think.
Soli Deo Gloria (Glory to God Alone): the justification of God's wisdom and power against papal usurpation and religion of human devising, honoring God's sovereign transcendence and providential predestination.
What does this mean? Really, what is, objectively speaking, giving glory to God, and what is taking away from that glory? Is the institution of bishop and priest of human devising, or does it have as its originator Christ Himself? We would say that, of course, God didn't have to establish a human-run organization to speak for Him on earth, yet since this is what He did (in our opinion), we are indeed bringing Him glory by upholding and honoring said Church, complete with its heirarchs, who have always been the ones charged with rightly dividing the word of truth.
Sola Gratia (By Grace Alone): redemption as God's free gift accomplished by Christ's saving death and resurrection. This was articulated chiefly in Pauline terms as justification by faith alone, as in the Augsburg Confession: "We cannot obtain forgiveness of sin and righteousness before God by our own merits, works or satisfactions, but receive God by grace, for Christ's sake, through faith, when we believe that Christ suffered for us and that for his sake our sin is forgiven and righteousness and eternal life are given to us."
Well, the Orthodox Church could say that we ascribe to
sola gratia, but
only in the sense that Christ has redeemed all of humanity through His incarnation, and that this redemption, already accomplished through His sovereign grace and mercy, is now to be applied to people individually. The boldfaced terms intend to call attention to the fact that to claim that you are simply using Pauline terminology to support a system of "merits, works, or satisfactions" is ignoring the earliest centuries of Christianity, where the whole idea of making satisfaction to an angry or offended God is completely unknown. It should be said that, in opposition to the corrupted version of Tradition that the medieval Roman Church put forth at the time of Augsburg, this statment makes perfect sense when taken in the light of the theological system it came out of--that of merits, of satisfaction, of appeasing God's justice and wrath. Yet it's beating a dead horse when it comes to Eastern Christianity, for the more ancient of ways to look at this--a way to which Luther himself never really was exposed--was completely devoid of this novel idea, articulated first by Anselm in the 1100s, iirc. Puts a whole new spin on why Christ died, and the significance of grace and works.
Sola Scriptura (Scripture Alone): the freedom of Scripture to rule as God's word in the church, disentangled from papal and ecclesiastical authority and tradition. Scripture is the sole access to Chrsitian revelation. Although tradition may aid its interpretation, its true (i.e. spiritual) meaning is its natural (i.e. literal) sense, not an allegorical one in lue of its natural sense.
Again, in the face of the corrupted traditions of the Latin Church, this was the Reformers only logical recourse. Yet they threw the baby out with the bathwater, so to speak, and ditched the genuine traditions due to lack of example. The reaction that was and is sola scriptura, however, loses face when it becomes apparant that, as noble an endeavor and idea as finding the "true (spiritual) meaning" of a Scripture is, it's truly an impossible objective, as no one's really been able to determine exactly what that spiritual meaning actually is.
The Church as the Believing People of God: constituted not by hierarchy, succession, or institution, but by God's election and calling in Christ through the gospel. In the words of the Augsburg Confession, it is "the assembly of all believers among whom the gospel is preached in its purity and the holy sacraments are administered according to the gospel." The sacraments appointed by Christ are two only - baptism and the Lord's Supper - and may be spoken of as "visible words", reflecting the primacy of preaching in Protestant conviction.
As to the first part, yes, the Church is the people of God, though instead of an either/or mentality--NOT by institution BUT by God's calling--we'd say that it's a both/and mentality--BOTH by institution AND by God's calling, as there are some in the true Church who do not truly believe, and such should not see themselves as progressing in salvation solely from being a part of the Church.
As to the boldfaced words: don't tell that to Lutherans, Anglicans, Presbyterians or Methodists! They would strongly disagree, as they also hold to a priesthood, confirmation (or first communion), marriage, holy unction, last rites, and (in the case of higher-church Anglicans) confession. That is primarily an idea held by the radical fringe reformers, whose descendants are the Baptists of today, among other groups including the Mennonites and Amish.
The Priesthood of All Believers: the privileged freedom of all the baptized to stand before God in Christ 'without patened human intermediaries' and their calling to be bearers of judgment and grace as "little Christs" to their neighbors. Pastor and preacher differ from other Christians by function and appointment, not spiritual status.
Absolutely. You might be surprised that we can say that, but we can. The (mis)conception that many Protestants have of the priesthood doesn't apply to us. We can especially agree on the bolded words.
The Sanctity of All Callings or Vocations: the rejection of medieval distinctions between secular and sacred or "religious" (i.e. monastic) with the depreciation of the former; and the recognition of all ways of life as divine vocations in their own right. "The works of monks and priest in God's sight are in no way whatever superior to a farmer laboring in the field, or a woman looking after her home". None is intrinsically more Christian than any other - an insight obscured by phrases such as "the holy ministry".
Again, absolutely. The only reason that it's called "the holy priesthood" and my job is not called "Ye holy Spanish Teacher"

is because Christ, by His very presence in the sacraments, by the initial establishment of the priesthood on the very Kingdom of God itself, it has always been holy, transfigured, brought into the Kingdom. Our jobs in the world are to do this very thing: to bring our professions before God, as priests, and have them transfigured by the grace of God for His glory. The former has already had this done to it by the Lord; the latter is being done by the Church members, as we cooperate with Him.
Weighing these principles I find Orthodoxy reaching to the same position of authority as Catholicism over the Body of Believers imposing the same dictates and claiming the same superiority through their traditions, ministry of priests and sacraments, adoration of saints and the claims to superior sanctity through monastic practices over the Body of Believers and although they don't claim the position of One Supreme Tyrant non-the-less impose 'little' Tyrants over the Body of Believers through the same means.
Has what I've said at least helped you see some of these things in a different light? That is, that we're not trying to do this to be tyrannical, but rather because we see a much different theological landscape than Protestants, born of a corrupted tradition, do?
I have read and followed many dialogues here to witness first-hand that your traditions, priests, sacraments and ascetics don't establish the unity such it intended to foster...
Again, attend services. We would say (with all due respect) that you can't really say that you've witnessed anything about us "first-hand" until you go and experience what this is all about. We are, in fact, united in worship, in doctrine, in faith and love.
...but through Baptist Theology we establish the liberty given to man by God to either walk in faith for continued in the bondage of sin under the guidance of a body of equals in both under His Lordship and through His Word.
I'd like to draw your attention to the boldfaced words. You had said originally that your theology covered Protestants as a group, in spite of doctrinal differences, and that the liberty espoused by the Scripture was one of individual worship and belief preferences, as per his/her individual "right" before God (again, these ideas of "rights" and "a body of equals" are very much the product of enlightenment- and post-enlightenment-era, western influence). Now the theology is Baptist only, and the liberty is one of either being freed from the world or continuing in darkness. Is the former definition what St. Paul meant by "liberty," or this latter one?
You certainly have unity of doctrine within (your particular) Baptist community, but continue to bear in mind that, in spite of unity of (your) essentials, there are other ideas seen in other groups with whom you claim "unity" as so essential that they impede real unity--hence denominations (divisions). We Orthodox would say we offer the same choice and hope, without making an apology for our essentials.
Now that might sound critical but it is only a means to establish from what prespective Believers stand when looking at Orthodoxy.
I appreciate the honest criticism, but I hope that what I've written might give you a place to "launch out" from and see the Christian Tradition in a new light that, amazingly (for me, it was, anyway) had existed and thrived for 2,000 years without the influence of rational, enlightenment, egalitarian thinking.
I don't even want to get into the fact that your gospel appears to have embraced divinity over atonement. Wasn't that the sin of Adam?
Well, we almost got through that post with my understanding everything you said.

You're gonna have to go into that one in more detail before I can say I understand that criticism...