But I believe the statement is only comprehensible in reference to God's Triune nature: Christ's nature as both fully human and fully divine and God's salvation plan for mankind.
Christ's question to the Father on the cross shows not that Christ wasn't God but that he was also a distinct divine personality in the Trinity and also fully human. If he had not been fully human, he could not have taken on our pain. Nor could he have died. If he was not God, he couldn't have lived a sinless life or wiped away our sins.
Evangelist John Stott wrote: "We are not to envisage God on a deck chair, but on a cross. The God who allows us to suffer, once suffered Himself in Christ, and continues to suffer with us and for us today. I myself could never believe in God were it not for the cross. In the real world of pain, how could one worship a God who was immune to it? Our sufferings become more manageable in the light of His. There is still a question mark against human suffering, but over it we boldly stamp another mark -- the Cross, which symbolizes divine suffering. The cross of Christ is God's only self-justification in such a world as ours."
Despite his indescribable suffering, Christ would not rescue himself, precisely because he was a co-conspirator in the salvation plan, which required him to fulfill his prophesied substitutional sacrifice.
As Bishop Fulton Sheen observed: "Every other person who ever came into this world came into it to live. Christ came into it to die. Death was a stumbling block to Socrates -- it interrupted his teaching. But to Christ, death was the goal and fulfillment of his life, the gold that he was seeking."
Christ died forsaken by God so that his people might claim God as their God; he endured abandonment so we would never be abandoned; he tasted hell so we'd never have to taste it ourselves; he endured loneliness so we'd never be alone.