More from Barth’s stirring sermons:

God with us! That is too strong a contradiction, not only over against our sins and sufferings but also against the nature of our existence down to the very deepest depths of its roots. God with us! That conflicts too much, not only with our unrighteousness, but more yet, with our righteousness; not only with the atrocities of history, but more yet with history’s supposed progress and achievements; not only with the misery on earth, but more yet, with the supposed happiness and satisfaction on earth. God with us! That subjects our total human nature to a judgment, to a No, that will leave nothing left of us, and will bow us under a grace, a yes, that we cannot comprehend. God with us! That is not only a better man, but a new man; not only a beautiful world, but an other world; not only a higher life, but an eternal life. God with us! That is redemption, but real, all-embracing serious, and therefore radical redemption. That is the fire of which Jesus spoke, the fire that wants to come forth out of the glow that He started. Hence the impossibility for us to look right into the glow; hence our helplessness in the presence of Jesus, now as then. Hence the earthquake, the disquietude, the confusion which inevitably arises, when the word of reconciliation is really preached and heard. Hence the alternative (either-or) with which we are inevitably confronted when we understand what is at stake. When we come to close to the glow in Jesus. (p. 118-19)

Barth has an awesome sermon on Luke 12:49 reflecting on Jesus’s statement that he came to kindle a fire on the earth:

Jesus used this strong word very consciously: I am come to kindle fire. Whatever gets into fire is not only changed, but it is transmuted in a manner unheard of, into something different from what it was. Wood ceases to be wood when in the fire; it becomes ashes and gas, light and warmth. Jesus meant to say: such transmutation, such radical change is what I bring and give. Just so he purposely used that other strong word: I am not come to bring peace, but a sword, the sword that brings death, that is, not just a change and an improvement in this existence with which we are acquainted, but a transition from this existence to an entirely unfamiliar one. Let us think for a moment that that which Jesus is and that which he wants, this Immanuel! God with us! is true; that it is not simply in the Bible, and spoken by a minister in the pulpit, but that it is simply true. What then? Clearly then something new begins, something as different from all that now is as ashes, gas, light and warmth are from wood, death from life.

~ Karl Barth, “Fire Upon the Earth!” in Come Holy Spirit, 118.

This notion of radical transmutation, of the supreme novum that Jesus brings about in achieving our salvation is what we are talking about whenever we talk about “apocalyptic.”