"The Resurrection is therefore an occurrence in history, which took place outside the gates of Jerusalem in the year A.D. 30, inasmuch as it there 'came to pass', was discovered and recognized. But inasmuch as the occurrence was conditioned its necessity and appearance and revelation, the Resurrection is not an event in history at all."
(Karl Barth, Epistle to the Romans, OUP, 1968, p.30. Emphasis added.)
At a luncheon of 200 Christian leaders held to honor theologian Karl Barth, Henry rose and identified himself as "editor of 'Christianity Today'" before asking Barth about his views on the historical fact of Jesus' resurrection. Barth retorted, "Did you say Christianity Today or Christianity Yesterday?" As the audience howled with laughter, Henry countered, "Yesterday, today, and forever."
After reading Barth's statement above again and again, I can only guess it means something like this:
1. The Resurrection occurred in history as an event that ‘came to pass’.
2. In this way, it is an event conditioned by historical processes.
3. Hence it looks as if it 'came to pass'.
4. Just like other historical event, this event is ‘discovered’ and ‘recognized’ by us.
5. Yet the Resurrection’s necessity, appearance, and revelation are not conditioned by history.
6. The Resurrection’s necessity, appearance, and revelation are first the free act of God, which was embodied out of his divine love.
7. And God’s act is his own being. Came in the person of Jesus Christ: a revelation.
8. Therefore the Resurrection was first an act conditioned by God himself in his free and loving act of necessitating, appearing, and revealing his own being in Jesus Christ.
9. And such act is transcendental. Its origin is beyond and above history.
10. That means the Resurrection transcends history instead of being conditioned by it. It is not merely an occurrence that ‘came to pass’ under the condition of historical processes.
11. Therefore our appropriation of the Resurrection is in fact a divine revelation conditioned by God himself rather than our own ‘discovery’ and ‘recognition’.
12. Our 'discovery' and 'recognition' of the historical Resurrection can only be real discovery and recognition when they are conditioned by the divine revelation which is in the Resurrection itself.
13. And in this way, all historical processes are conditioned by the Resurrection rather than the other way around.
14. Hence it is not ‘an event in history at all’.
To Barth, the historicity of the Resurrection is precisely the reason why it is not historical. Hence we can't simply say Barth denied or affirmed the historicity of the event. He affirmed something different altogether: its meta-historical reality.
Does that clarify or make sense? If you have another interpretation, please share.