I haven’t read much of Karl Barth before, but this excerpt strikes me as spot on:
We must once and for all give up trying to be self-made individuals. Let us cease preaching by ourselves, being right by ourselves, doing good by ourselves, being sensible by ourselves, improving the world by ourselves. God wants to do everything, certainly through us and with us and never without us; but our participation in what he does must naturally originate and grow out of his power, not ours. O, how we could then speak with one another. For whatever does not grow out of God produces smoke, not fire. But that which is born of God overcomes the world.
– from Barth’s commentary on Luke 1:5-23; quoted in Watch for the Light: Readings for Advent and Christmas (Orbis)