Frank Jehle, in his very fine book Ever Against the Stream: The Politics of Karl Barth, 1906-1968, offers this wonderful quote from Barth.
"There are no areas of which we can say: God has nothing to do here or this is none of God's business. It is not true that there is a religious sphere in which we are willing to listen and, at the same time, another sphere where life has its own laws, where we may not allow the light of God to enter in. But just as the whole is met by mercy, in the same way the whole is also put under the discipline of grace. God wants and needs nothing less than everything!" [Karl Barth, Predigten 1921-1935, ed. Holger Finze (Zürich: Theolgischer Verlag Zürich, 1998), 457f]
Frank Jehle, Ever Against the Stream: The Politics of Karl Barth, 1906-1968, trans. Richard and Martha Burnett (Grand Rapids: Eerdmans, 2002), 34