There are always two kinds of important theological discussion going on: those taking place in the public forum for everyone to see, and those taking place in academia between scholars and writers. While the former kind is more visible, it is the academic conversations which typically inform and fuel the public dialogue. Increasingly in our postmodern society, the two are bleeding into each other, so that laymen read academic literature, and scholars appeal to a popular audience.
It is largely for this reason that John Piper's The Future of Justificationis so important. The subtitle is "A Response to N.T. Wright," and that is exactly what this book presents: answers (and some questions) concerning the former Bishop of Durham's unique and often troubling statements concerning Christian salvation and what it entails, the nature of the Gospel, and the role of works in all this. Piper is more pastoral and less academic than Wright, but he is an astute reader and his concerns are real.
N.T. Wright is an Anglican minister and theologian who is often associated with the so-called "New Perspective on Paul" initially introduced and made famous by Krister Stendahl and E.P. Sanders (though those two are quite different in their views). The New Perspective attempts to re-cast the apostle Paul's theology in terms of the politically charged statements that find their way into his epistles.
New Perspectivists claim that the essence of the Gospel is that Christ is the true Lord of heaven and earth, basing this on the "gospel language" Paul employs that mirrors the "gospel language" of the Roman Caesars. While orthodox Christians certainly affirm that Christ is Lord of heaven and earth, we also understand the Bible to present the Gospel in terms of salvation from sin, that Christ put death to flight on our behalf and saves us through His substitutionary atonement.
Whether N.T. Wright believes this salvific truth isn't Piper's concern in this book. Instead, he compares what Wright says about the Gospel to what the New Testament writers (mostly Paul!) say about it, as well as to historic Christian doctrinal statements such as the Westminster Confession of Faith. Piper is irenic and pastoral in his approach, though he also evidences a disarming ability to deal with scholarship, exegesis, and logic at a high level.
That's not to say The Future of Justification is overly academic. While it is intellectually rigorous, it's also apprehendable to the layman, for whom it is intended. Piper points out that the reason he deals with Wright rather than other New Perspectivists (like James D.G. Dunn and Sanders) is that Wright is such a compelling writer and scholar that his readership is much more broad, and that lay churchgoers are reading and interacting with him.
Some may wish to point out that Wright has to some extent distanced himself from the strict New Perspectivists, and that he has even debated James Dunn on the issue, and it's a fair point. Piper may be ill-advised couching his argument as against Wright's supposed New Perspectivism; at the same time, he accurately outlines Wright's views on justification and deals with them directly, and this is an important book that should be read by anyone aware of the current dialogue concerning Christian justification and salvation.