To cut straight to it, I think Piper gets it wrong in his recently released book 'The Future of Justification.' Despite his efforts to engage with Tom Wright whilst writing the book and trying to understand where Wright is coming from (a model for a scholarly book engaging another theologian), Piper fails to understand Wright's fresh perspective. And the answer lies in the cover of Piper's and Wright's books. N.T. Wright’s book on justification and Paul has a picture of the Apostle Paul on the cover, whereas Piper’s book on justification and Paul has a picture of Martin Luther.
I’m not saying that Piper is more devoted to Luther than Paul or that Wright is more devoted to Paul than Piper is… only that the picture does express, at least at some level, why Piper just doesn't get it. Piper is commitmented to a Lutheran understanding of the gospel (gospel = justification), and has an apriori belief that the reformation is NOT over.He believes that Wright’s view will be co-opted into the Roman Catholic view (183). Piper then issues his own “Here I Stand” section, where he clearly and unabashedly affirms the traditional Protestant understanding of justification by grace alone through faith alone on account of Christ’s righteousness alone (184) in defiance against Roman Catholicism.
However, the Reformation is long ended. The Reformation was about protesting against the abuses and false teaching of the Western Church and trying to change the church. And the last I saw, the protesters (The Protestant Churches) have given up on trying to reform the Roman Catholic Church. I hardly expect any Protestant Churches to now expect to be reunited with Roman church, let alone each other. We've settled down into the current denominational plurality that exists in the west. Wright's work on Paul offers a way forward from the current denominational impasse. However, Piper fears that this solution will be taken hostage by some tough, Catholic apologist. And that is why his book fails to understand NT Wright.