If you're interested in reading the dialogue between the the theologians at Tubignen and Patriarch Jeremias II of Constantinople, you can find a translation of the letters on Amazon. Oddly and unfortunately, it doesn't contain a copy of the Augsburg Confession which was sent to Constantinople. Some excerpts can be found here, but be aware that this website tends towards the traditionalist end of the spectrum.
If you want to study this in depth then you might read about the correspondence between the early Lutherans and Patriarch Jeremiah II regarding the Augsburg Confession, which you can read about in this book. You can also read about the EO Synod of Jerusalem in 1672 which rejected the Protestant teaching.
It really boils down to the solas. EO never held to sola scriptura and considers it a source of error. Protestantism doesn't exist without some form of it.
I've heard that this book is a good overview of early Protestant-Orthodox conversations.
Luther was just appealing to the idea of a Greek Orthodox Church to show that there were non-Roman Churches out there to give himself legitimacy. He hadn't actually considered their doctrines. He was just so convinced that he was right that he assumed non-Roman Churches would agree with him. When later Protestant scholars actually corresponded with the Orthodox on theology it did not go so well because they discovered that they were actually in agreement with nobody but themselves.
You're thinking of correspondence that happened between Lutheran theologians and Constantinople after Luther's death:
https://www.amazon.com/Augsburg-Constantinople-Correspondence-Theologians-Confession/dp/0916586820
A lot of people have read or been influenced by Wolfmueller's book about "American Christianity"
As a former evangelical, I think you might really enjoy it
https://www.amazon.com/American-Christianity-Failed-Bryan-Wolfmueller/dp/075864941X
The Philokalia isn't so much a late work as a recently (lol) compiled collection of works on prayer. It's quite a lot and not something I'd put forward as an introduction even for a high-level reader. It's full of practical advice, but should still be taken under the guidance of one who is very experienced in a disciplined life of prayer, as more than a few, unfortunately, have seen some rigorous guidance meant for monastics, applied it without adjustment to their own lay life, and burned themselves out.
If you bear the above in mind and weigh the suggestions carefully, it can be a productive read.
Since your background in philosophy is so extensive and since you're so familiar with German thinking, <em>Augsburg and Constantinople: The Correspondence between the Tubingen Theologians and Patriarch Jeremiah II of Constantinople on the Augsburg Confession</em> offers translations of the debate over letters between Lutheran theologians and an Ecumenical Patriarch. They spend a lot of time discussing the place and role of Holy Tradition, and other Protestant-specific objections, but the whole conversation is generally informed by two fundamentally different approaches the Faith. The Lutherans ardently defend some Roman Catholic positions the Orthodox find objectionable, which was interesting to see.
But it does nosedive into some hard and very technical philosophical debate more rapidly than I anticipated, you may find it a less distressing experience than I lol
This is more for history buffs, so is not precisely what you are asking for. But if any are curious how us two first met to discuss similarities and differences, this is it.
If you're ready to really dive into theology, The Proper Distinction Between Law and Gospel by CFW Walther is the go-to text among many Lutheran denominations. It's a collection of his lectures from his time as a professor at Concordia Seminary.
This might interest you.
https://www.amazon.com/Augsburg-Constantinople-Correspondence-Theologians-Confession/dp/0916586820
It is some letters early Lutherans wrote to the Orthodox Patriarch in Constantinople. He wrote back what he liked and disagreed with, which started a dialogue. Spoiler alert: eventually the Patriarch said “I see you as friends, but don’t approach me on this again”.
I personally have two gripes. They do allow asking for “intercession” from dead saints. As they view it, it is no different than asking members of your church to pray for you. However isn’t asking for anything still praying?
Second is Theosis (deification). At best, this is just a poor choice of words and it just means returning us to our Adam like state prior to the original sin. At worst, it approaches what Mormons believe, and I know a few Mormons who like to use Theosis to justify “As God is we shall be”. I think the Orthodox view lies somewhere between the two extremes.
This book is a set of letters between 1570's Lutherns and Patriarch Jeremiah II. He really details the Orthodox view of the sacraments and other topics from scripture, tradition, and reason.
https://www.amazon.com/Augsburg-Constantinople-Correspondence-Theologians-Confession/dp/0916586820
There's a fascinating book called Augsburg and Constantinople, that's a collection of letters sent between some early prominent Lutheran theologians and the patriarch of Constantinople himself. I mean the exchange is just...well, fascinating. It's a bit of a dense read, but I highly recommend it.
I'm not a fan of syncretism either. While Halloween was implemented as a means of Christianizing pagan holidays in an attempt to evangelize pagans, I think the way that they chose to do so is horribly misguided.
Doing something on the same day as a pagan holiday makes sense. It's providing a Christian alternative. Dr. Robert Bennett goes into detail on how the Malagasy Lutheran Church in Madagascar sets up events during the local Animist festivals in his book I Am Not Afraid: Demon Possession and Spiritual Warfare.
The big difference here, is that the Christian events the Lutheran church does in Madagascar draw no content from the pagan festivals. They allow for no overlap and no creeping in of paganism. In fact, they do the exact opposite, incorporating "exorcism of place" prayers which often result in the manifestation and expulsion of demons from the non-Christians in the audience. Halloween, on the other hand, incorporates many pagan ideas, including seeking to communicate with the spirits of the dead.
Luther's Spirituality from the Classics of Western Spirituality series
Calvinism really a bad name for it. It's not exactly central to Calvin's thought, and he certainly wasn't the first to see the scriptures in that way. Luther did before Calvin, and Augustine before Luther (I'd also argue that Paul did before Augustine, but that's a bit presumptuous).
Given your flair, if you wagnt to understand Calvinism, I would say that you should start by reading Luther's The Bondage of the Will
On page 228 - 230 of this book which is probably the book you got when you started catechism classes. It's talked about in the Office of the Keys near Confession and Absolution.
When I get a moment, i'll type out a few quotes for you, but i'm supposed to be doing something.