Very challenging and thought-provoking book discussing the motivation for our obedience. Commonly we are told to obey God out of gratitude for God's grace to us in the past. While affirming the importance of gratitude, Piper argues that it is a poor motivation for obedience, which is why God offers us so many promises for grace in the future as motivations. He then demonstrates how faith in God's future grace offers the best motivation for victory over various plaguing sins and how it enflames our passion for God.
I found myself challenged several times through the book, yet I found that Piper had the weight of Scripture on his side. Highly recommended, but come ready to consider what he says. I also recommend the 1 chapter a day for a month approach.