“Redemption terminology in the NT is so bound up with Christ’s work for and in the church that to extend it to whatever good we do in the broader world risks a shift in focus. Not for a moment do I want to deny that we are to serve as salt and light, that exiles may be called to do good in the pagan cities where Providence has appointed them to live (Jer 29), that every square foot of this world is under Christ’s universal reign (even though that reign is still being contested), that the nations of the world will bring their “goods” into the Jerusalem that comes down from above. But many of those who speak easily and fluently of redeeming the culture soon focus all their energy shaping fiscal and political policies and the like, and merely assume the gospel. A gospel that is merely assumed, that does no more than perk away in the background while the focus of our attention is on the “redemption” of the culture in which we find ourselves, is lost within a generation or two. At the same time, I worry about Christians who focus their attention so narrowly on getting people “saved” that they care little about doing good to all people, even if especially to the household of God. Getting this right is not easy, and inevitably priorities will shift a little in various parts of the world, under various regimes. Part of the complexity of the discussion, I think, is bound up with what the church as church is responsible for, and what Christians as Christians are responsible for: I have argued that failure to make this distinction tends to lead toward sad conclusions.”
You can read the entire conversation with Derek Thomas here: Don Carson Talks About Culture.