On his blog Reformedish, Derek Rishmawy gives his thoughts on Gabe Martini’s Eastern Orthodox commentary on the current sanctification debate swirling in the Reformed world (and especially The Gospel Coalition). He notes that there is a major lacuna in Martini’s post: he doesn’t address the Reformed doctrine of union with Christ. Because of the reality of our union with Christ, many old charges against Reformed Protestantism—like double imputation being a “legal fiction”—don’t carry much force.
Derek provides some great Reformed resources on the subjects of sanctification and union with Christ, and I would encourage the reader to check out his post.
I’ll make one minor critique of his post (and this is more a matter of semantics than substance): he suggests an openness to the language of “synergism/cooperation” when it comes to the Reformed doctrine of sanctification. Now I suppose that it is possible to define these terms in a way that is amenable to Reformed theology, and quite orthodox folks like R.C. Sproul and Harry Reeder have indeed embraced them. Still, I would prefer not to use them at all, precisely because they can be so misleading (as Bill Evans has argued here). But neither would I want to use the language of “sanctification by faith alone,” because that could imply the sort of passivity/quietism of a getting-used-to-your-justification view of sanctification that should equally be avoided. I think a more thoroughgoing Reformed conception of sanctification would be characterized as “bilateral monergism”—which simultaneously recognizes both the sufficiency/efficacy of God’s grace, and also the necessity/instrumentality of our effort and good works in sanctification.