What is the glory of God? A simple yet profound question. In a narrow sense it is helpful to think about the glory of God in terms of the sum total of his perfections (which includes every aspect of his character) manifested in their radiance to humanity.
Where is this glory most clearly displayed? I believe that the cross is the greatest manifestation of the glory of God. It is here, in the darkest place that the bright rays of glory shine most brilliantly. The cross is an unprecedented glimpse into the glory of God. It is a paradox for it is the least likely place humanity would ever expect to find God much less find him displaying his splendor! The shameful cross is God’s chosen vehicle to show forth his perfections.
In his commentary on the gospel of John D.A. Carson asserts this very fact. “Jesus’ death was itself the supreme manifestation of Jesus’ glory. It is not just that the shame of cross is inevitably followed by the glory of the exaltation, but that the glory is already fully displayed in the shame…his being glorified is not a reward or recompense for his crucifixion; it inheres in his crucifixion” (emphasis mine). 
 D.A. Carson, The Pillar New Testament Commentary: The Gospel According to John (Grand Rapids: William B. Eerdmans Publishing Company, 1991), 437, 444. The last part of this quotation is Carson quoting F.F. Bruce.