If you were a fan of the comic strip Calvin and Hobbes, you might remember that Calvin had a transmogrifier machine. The boy Calvin leads his imaginary tiger Hobbes up to a cardboard box with the word “Transmogrifier” handwritten on it, and explains, “You step into this chamber, set the appropriate dials, and it turns you into whatever you’d like to be.” Hobbes wryly observes, “It’s amazing what they do with corrugated cardboard these days.”

The promise of true change is a little unbelievable, isn’t it? It’s the stuff of comic strips and daydreams.

But make no mistake: this is exactly what Christianity promises—true and real change. Divine pardon. Reconciliation with God. Smashed idols. A new spirit. A new self. A new family.

Since this year’s Together for the Gospel theme is the Underestimated Gospel, we thought we’d jump on the bandwagon and devote the pre-T4G Journal to the underestimated doctrine of conversion. Forget Calvin’s transmogrifier machine. How about a whole new creation!

9Marks is deeply interested in the doctrine of conversion (it’s the fourth mark) because it’s tightly tied to the doctrine of the church. If the church is a house, conversion is the timber. The timber you use will dramatically affect the kind of house you get. Will you include the timber of divine sovereignty? Human responsibility? Repentance? Faith? My own article on the corporate component of conversion explores these matters further.

But start with Jared Wilson’s reflections on the beauty of the doctrine and Owen Strachan’s historical observations. Thomas Schreiner and Steve Wellum also help us to get our doctrine right. This is critical, friends. Owen’s piece especially will help you to see why, as will Bobby Jamieson’s instructive book review on Revival and Revivalism.

Once you’ve got the doctrine right, you need to think about how it connects to the life of the church. For that purpose we’ve called in Jeramie Rinne, Michael Lawrence, Mike Mckinley, and Shai Linne. Zach Schlegel’s review of Finally Alive might also surprise you with its pastoral insight.

There is underestimated power in the doctrine of conversion, but only if we get it right. Have you? Have your people? Does it show up in the habits, practices, and structures of your church’s life together?