Reddit mentions of Introducing Eastern Orthodox Theology

• The Orthodox Faith, by Fr. Thomas Hopko, is online and free.
  
  
• The Orthodox Church and The Orthodox Way, by Metropolitan Kallistos Ware, are a pair of very good introductory books.
  
  
• Introducing Eastern Orthodox Theology by Fr. Andrew Louth, is another good theological introduction.

Introducing Eastern Orthodox Theology is a readable introduction based on a lecture series.

Light from the Christian East was written by someone in the Reformed tradition who nevertheless does a pretty good presentation of Orthodoxy.

Orthodox Christianity (3 vol.) is probably the most comprehensive overview by a contemporary Orthodox theologian and churchman.

Ah, I see. I think I was misunderstanding you. I certainly agree that because Christ is incarnate, whole and undivided and one with the Father, the Church ought to be one as well (see, for example, John 17:20-24). And the Eastern Orthodox and Roman Catholics would agree, too. The question is whether that "one" Church is the Eastern Orthodox Church, and this is where the Eastern Orthodox material I've come across (mostly blogs, but also in books and in conversation) turn to the other kinds of claims I was mentioning.

So yes, the incarnation is very important to Eastern Orthodox ecclesiology (and to Roman Catholic and most Anglican ecclesiology), but it's when distinguishing between the different ecclesiologies that we have to turn elsewhere, if that makes sense.

Some resources can be found here: Introducing Eastern Orthodoxy
and here. Notice especially in the article I linked to that he discusses the Church's Incarnational significance but also discusses bishops, historical continuity, etc.

Light From the Christian East by James R. Payton - written by a non-Orthodox scholar who is sensitive to accurately describing Orthodox theology while making them accessible to non-Orthodox.

The Orthodox Way by Kallistos Ware - not to be confused with his older classic, The Orthodox Church, which describes the historical development of the tradition. This work is more personal because of its focus on how Orthodox theology applies to the life of a Christian. Ware is an Orthodox bishop who has been famous for decades for his attempts to introduce Eastern Christianity to a popular audience.

Introducing Eastern Orthodox Theology by Andrew Louth - Louth is a gifted Russian Orthodox scholar and priest who writes ably on a number of topics.

The Mystical Theology of the Eastern Church by Vladimir Lossky - Lossky is one of the most influential Russian Orthodox theologians of the 20th century. This book is a classic introduction published in the 50s, and also advocates for a certain understanding of Orthodoxy that emphasizes its distinctiveness (the "mystical" part) from Western theology.