And yet the Son on the Cross cried out 'My God, my God, why have you forsaken me?' To ignore that is to reduce the sacrifice to a 'happy ever after' fairy tale. But to accept it you have to accept it as unjust and unnecessary.
I guess it depends on what book you're reading.
In his book "Jesus Interrupted", Bart Ehrman highlights a fundamental contradiction:
The death of Jesus as recounted in Mark 15:16-39 is notable in that Jesus doesn't say a word until he utters what has become known as "The Cry Of Dereliction". This is a Jesus who doesn't know what's going on and genuinely wants to know why God has left him like this. It's a Jesus full of despair and that's how he dies.
Compare that to how Luke tells it (Luke 23:26-49) and you'll see that Jesus is anything but silent. Even when he's nailed to the cross Jesus knows what the score is and he appears to be in communion with God as he tells his father to forgive them. Then Jesus says "Father, into your hands I commend my spirit".
How different to the forsaken and abandoned Jesus depicted by Mark! Luke's version of Jesus knows exactly what's going on and has no need to cry out " "Eloi Eloi lama sabachthani?"
In Mark, Jesus has been rejected by everyone. Betrayed by one of his own and denied three times by his closest follower. He was mocked by the priests, rejected by the Jews and condemned by the Romans. Even those being crucified with him, mocked Jesus. At the end, Jesus is in agony and despair and he's unsure of the reasons why he has to die.
This is what Mark portrayed - a lost and abandoned Jesus. It's not for nothing that the quote you made is often known as the "Cry of Dereliction"
All-in-all, quite contradictory to Jesus' death scene in Luke.
Here we see a Jesus who has no need to ask God why he's been forsaken. This Jesus knows the reason he must die and he spends his dying moments showing more concern for others than for himself.
Rather than uttering a cry of despairing hopelessness ("Why have you forsaken me?"), in Luke, Jesus prays to God and says "Father, into your hands I commend my spirit". This is not the forsaken, abandoned and confused Jesus of Mark, rather, Luke tells us about but a Jesus who knows full well why he has to die and is fully aware of the reasons why he is suffering so.
I don't believe in what the Bible has to say but I do feel that each author that contributed their specific piece was their own person.
These peoples were individuals and they were saying it in the way they wanted to say it. We should let them have their say, even if it throws up discrepancies, inconsistencies and contradictions in the narratives.
What believer like to do is make one overarching story of Jesus from what are, in some cases, quite different accounts. In their take on the Gospels, Jesus says and does everything that they say he did.
So, whatever messages that Mark, Luke, etc, where trying to convey tend to get glossed over by believers and become lost in translation. Looking at the stories their way means stripping the writers of their integrity as an author and replacing the author's meaning with their own.