The cross is a catastrophe

Apart from the Resurrection Christ’s death on the Cross is a catastrophe, not a saving fact. The faith of the disciples in the Messiah was shaken by the crucifixion, until the appearance of the Risen Lord gave them back their faith in Christ, and at the same time fulfilled it. Then they were able to say, “God was in Christ, reconciling the world unto Himself”, and this confession of faith fulfilled what they had already seen in the life of the Lord as the divine activity of the Saviour.—Emil Brunner, The Christian Doctrine of Creation and Redemption, 335