If you haven’t read John Piper’s Future Grace, get it! If you see the book and pass out because of its size, read his Prayer-of-Jabez sized version, Battling Unbelief. If you just aren’t a reader and would consider yourself a visual learner, get the Battling Unbelief DVD!
Why, you may ask? Because Piper here practically explains how justifying faith sancitifes. For those who don’t bat around theological terms, I mean this. Many people have erroneously taught and believed that salvation is a one-time decision to come to Christ for forgiveness of sins and eternal life. That is only partially true. Justification, which is a part of salvation, comes by God’s grace through our faith in the satisfactory work of Jesus on the cross in our place. But there is more to salvation than justification. When we believe, we are converted from being God’s enemy to being God’s adopted child. Thus we are saved to live for Him as He is now our Father and our King.
But how do we live for Him? Through will-power? Teeth-grinding determination? Piper argues that we live for Him through faith in God’s promises. In other words, the desire to sin is killed when we believe God’s promises more than we believe sin’s promises. And this faith is a continuation of the initial faith that brought about our justification. He follows the Puritan Thomas Chalmers’ argument in his sermon, “The Expulsive Power of a New Affection”, which is also worth reading. This was probably the hardest of Piper’s books on a practical level for me. But I pray that God will kill sin at the root in my life and yours through the greater treasuring of Him and His promises.