10 Says one, If he had this power, why, when the Jews insulted him on the cross and said, “If he be the Son of God let him come down from the cross,” did He not come down, to show them His power by coming down? Because He was teaching us patience, therefore He deferred the demonstration of His power. For if He came down, moved as it were at their words, He would be thought to have been overcome by the sting of their insults. He did not come down; there He remained fixed, to depart when He would.
For what great matter was it for Him to descend from the cross, when He could rise again from the sepulchre? Let us, then, to whom this is ministered, understand that the power of our Lord Jesus Christ, then concealed, will be made manifest in the judgment, of which it is said, “God will come manifest; our God, and He will not be silent.” Why is it said, “will come manifest”? Because He, our God—namely, Christ,— came hidden, will come manifest. “And will not be silent:” why this “will not be silent”?
Because at first He did keep silence. When? When He was judged; that this, too, might be fulfilled which the prophet had foretold: “As a sheep He was led to the slaughter, and as a lamb before his shearer is dumb, so He opened not His mouth.” He would not have suffered did He not will to suffer: did He not suffer, that blood had not been shed; if that blood were not shed, the world would not be redeemed. Therefore let us give thanks to the power of His divinity, and to the compassion of His infirmity; both concerning the hidden power which the Jews did not recognize, whence it is now said to them, “You neither know me nor my Father,” and also concerning the flesh assumed, which the Jews did not recognize, and yet knew His lineage: whence He said to them elsewhere, “You both know me, and you know whence I am.”
Let us know both in Christ, both wherein He is equal to the Father and wherein the Father is greater than He. That is the Word, this is the flesh; that is God, this is man; but yet Christ is one, God and man.
Source: Tractates on the Gospel of John (New Advent)