The wondrous theme of the Bible that frightens so many people is that the only visible sign of God in the world is the cross. Christ is not carried away from earth to heaven in glory, but He must go to the cross. And precisely there, where the cross stands, the resurrection is near; even there, where everyone begins to doubt God, where everyone despairs of God's power, there God is whole, there Christ is active and near. Where the power of darkness does violence to the light of God, there God triumphs and judges the darkness.
From "The Story of Dietrich Bonhoeffer" by Michael Van Dyke, page 68.