Greg Gilbert. “Addendum: WHAT IS THE GOSPEL?” in Proclaiming a Cross Centered Theology. Wheaton: Crossway, 2009.
to proclaim the inauguration of the kingdom and the new creation and all the rest without proclaiming how people can enter it—by repenting and being forgiven of their sins through faith in Christ and his atoning death—is to preach a non-gospel. Indeed, it is to preach bad news, since you give people no hope of being included in that new creation. The gospel of the kingdom is not merely the proclamation of the kingdom. It is the proclamation of the kingdom together with the proclamation that people may enter it by repentance and faith in Christ. (126-127)
I believe it is wrong ever to say that non-Christians are doing “kingdom work.” A non-Christian working for human reconciliation or justice is doing a good thing, but that is not kingdom work, because it is not done in the name of the King. C. S. Lewis was wrong; you cannot do good things in the name of Tash and expect Aslan to be happy about it. (129)
As I’ve argued before, I believe that many in the so-called emergent church—for all their insistence about how astonishing and surprising their gospel is—have missed entirely what really is astonishing about the gospel. That Jesus is king and has inaugurated a kingdom of love and compassion is not really all that astonishing. Every Jew knew that was going to happen someday. What is truly astonishing about the gospel is that the messianic King dies to save his people—that the divine Son of Man in Daniel, the Davidic Messiah, and the suffering servant in Isaiah turn out to be the same man. That, moreover, is ultimately how we tie together the gospel of the kingdom and the gospel of the cross. Jesus is not just King, but crucified King. Next to that, what many in the emergent church are holding out as an astonishing gospel is not astonishing at all. It’s just boring. (130)
There is only one command that is actually included in the gospel itself (whether broad or narrow): repent and believe. That is the primary obligation on human beings in this age, and therefore it must be our primary emphasis in our preaching, too. (130)