Christ is here condemned by a unanimous decision of the ecclesiastical court for confessing that He is the Son of God. Our first parents wanted to be like God. If this wrong was to be atoned for, if we were once again made to share in the true divine nature, 2 Pet. 1, and if we were again to be given the power to become the children of God, John 1, then, for that reason, the true only-begotten Son of God had to allow Himself here to be publicly condemned for confessing to be God’s Son.
So also the Lord publicly confesses that He thus suffers as the Christ, that
is, as the truly anointed King and High Priest, and that He takes His kingdom
upon His shoulder, Isa. 9. And, as the true High Priest, He intended to offer
Himself up to God as a sweet fragrance. For that reason—since Christ is God’s
Son [and] our King and eternal High Priest—His suffering and death has such a power that it serves as payment for our sin. Thus, to that end God disposes [so directs things] that in the midst of His passion Christ publicly confesses to be God’s Son and our only King.
(Johann Gerhard, An Explanation of the History of
the Suffering and Death of our Lord Jesus Christ, pp. 133-134)