Trembling and shaking the earth participated in the agony of the man on the Cross and in the despair of all those who had seen in him the beginning of the new eon.
Trembling and shaking the earth proved that it is not the motherly ground on which we can safely build our houses and cities, our cultures and religious systems. Trembling and shaking the earth pointed to another ground on which the earth itself rests: the self-surrendering love on which all earthly powers and values concentrate their hostility and which they cannot conquer.
Since the hour when Jesus uttered a loud cry and breathed his last and the rocks were split, the earth ceased to be the foundation of what we build on her. Only insofar as it has a deeper ground, can it stand; only insofar as it is rooted in the same foundation in which the Cross is rooted, can it last.
Paul Tillich in The New Being