In my opinion, there's way too much needless debate in Reformed theological circles on whether the finished work of Christ-the gospel-effects salvation for individual sinners (the "penal substitionary atonement" group) or if it brings about a renewed creation (the "God is on a mission to restore all things to Himself through the person and work of Jesus Christ" group). In my book Unfashionable, I address this issue. Maybe I'm missing something, but it just doesn't seem that complicated to me.
In the book, I write:
Jesus is the divine curse-remover and creation-renewer. Christ's substitutionary death on the cross broke the curse of sin and death brought on by Adam's cosmic rebellion. His bodily resurrection from the dead three days later dealt death its final blow, guaranteeing the eventual renewal of all things "in Christ."
The dimensions of Christ's finished work are both individual and cosmic. They range from personal pardon for sin and individual forgiveness to the final resurrection of our bodies and the restoration of the whole world. Now that's good news—gospel—isn't it? If we place our trust in the finished work of Christ, sin's curse will lose its grip on us individually and we will one day be given a renewed creation. The gospel isn't only about reestablishing a two-way relationship between God and us; it also restores a three-way relationship among God, his people, and the created order. Through Christ's work, our relationship with God is restored while creation itself is renewed. This is what theologians mean when they talk about redemption. They're describing this profound, far-reaching work by God.
Of course none of this is available for those who remain disconnected from Jesus. Sin's acidic curse remains on everything that continues to be separated from Christ. We must be united to Christ by placing our trust in his finished work in order to receive and experience all the newness God has promised. For, as John Calvin said, "As long as Christ remains outside of us, and we are separated from him, all that he has suffered and done for the salvation of the human race remains useless and of no value for us." But for all that is united to Christ, everything false, bad, and corrupting will one day be consumed by what is true, good, and beautifying—and this includes the material world.
Update: In the comment section below, Bill points out an excellent quote from Mike Wittmer's book Dont Stop Believing. Wittmer sums up the whole thing well, in my opinion, when he writes: "Penal substitution explains the heart of Christus Victor-how exactly Christ defeats the Devil. Christus Victor supplies the larger context for penal substitution."