When our Lord Jesus cried out, "Eloi, Eloi, Lema Sabachthani," He was quoting the Psamist. And in quoting the Psalmist, He was also fulfilling prophesy which nobody before that time had any idea was a prophetic Psalm. And He was identifying with mankind to the deepest depth of our humanity.
Of course none of this was play acting. When Jesus cried out, His cry was a totally real cry of one feeling all the pain of being forsaken by God.
But this very real cry was so staged, so planned, so contrived. To use a profane comparison, it was like a joke that nobody knew was a joke until they heard the punch line.
Every day it is so hard for us humans not to accuse God with questions of, "how is this fair?" and "God, where are you in all of this?"
With this cry of The Lord Jesus, we get a large part of the answer, He has not forsaken us, He's in it with us.
The Psalmist goes on to say out of his own experience, "He has not despised or abhorred the affliction of the afflicted." We know that to be true for God's Beloved Son was the Afflicted One who is now highly exalted, and making intercession for us poor lonely souls.