One question that is debated from time to time is this: is Eastern Orthodox (EO) theology compatible with Reformed theology? Having read several different resources by EO theologians, I believe the answer is quite clear: no. There are big differences in the areas of Scripture, sin, redemption, liturgy, and piety, just to name a few.
I appreciate the way Michael Horton describes it in his contribution to Three Views on Eastern Orthodoxy and Evangelicalism. Though I’m not a huge fan of these type of “viewpoints” books, Horton’s sections are quite clear and compelling. Here’s a summary (though I urge our readers to read beyond this if interested in the debate):
“The heart of our differences emerges over the material principle: justification by grace alone through faith alone because of Christ alone. …Despite agreements noted above, the Christian East…possesses an inadequate view of sin. This becomes apparent in its treatment of original sin, excluding inherited guilt from the picture and embracing a synergistic view of regeneration as well as a medicinal view of justifying grace” (p. 128-9).
“Orthodoxy’s apparent denial of original guilt and its reticence toward legal categories cannot help but lead to a denial of the imputation of Christ’s righteousness, or ‘justification.’ Orthodox theologians frequently dismiss the entire discussion of justification as a Western debate, although it was at the heart of Jesus’ controversy with the Pharisees, of Paul’s controversy with the Galatians, and of the writer of the book of Hebrews’ controversy with the Judaizers who wanted to return to the shadows of Jewish temple ritual, including its sacrifices” (p. 134).
“Any view of union [with Christ] and recapitulation that denies that the sole basis for divine acceptance of sinners is the righteousness of Christ and that the sole means of receiving that righteousness is imputation through faith alone apart from works is a denial of the gospel” (p. 137).
“Orthodoxy has many healthy emphases, but its denial of the full seriousness of sin and its consequently high appreciation for the possibilities of free will keep it from recognizing the heart of the gospel” (p. 139).