Mark 15:34
Christ's Cry of Dereliction: Why Hast Thou Forsaken Me?
St. Gregory clarifies that when Jesus cried out on the cross, He was not truly forsaken by the Father or His divine nature. Instead, He was speaking on behalf of humanity, representing our fallen and forsaken state so that we could be saved.
Of the same kind is the expression, "My God, My God, why have You forsaken Me?" It was not He who was forsaken either by the Father, or by His own Godhead, as some have thought, as if It were afraid of the Passion, and therefore withdrew Itself from Him in His Sufferings (for who compelled Him either to be born on earth at all, or to be lifted up on the Cross?). But as I said, He was in His own Person representing us. For we were the forsaken and despised before, but now by the Sufferings of Him Who could not suffer, we were taken up and saved. Similarly, He makes His own our folly and our transgressions; and says what follows in the Psalm, for it is very evident that the Twenty-first Psalm refers to Christ.