Mike,
The events that transpired at the cross and the degree of anguish/suffering that Christ/God endured may be more understandable than we may think.
During Christ's lifetime, He had enjoyed a very special "oneness" with His Father. It was a spiritual relationship that had progressed to the point that Jesus knew the mind of God and whatever He said or did was in accordance with the "will of God".
(This is our example. It is possible and of the utmost importance that we enter into such a relationship with God whereby God is "in us" as He was "in Christ".)
Jesus began to experience a separation from God at Gethsemane. From a Spiritual perspective, He could no longer sense God's presence. It was almost more than He could bear.
As time progressed leading up to His Death, Christ resigned himself to His ultimate fate. He realized that a total separation from God would end in Death. He accepted this, even though it generated extreme anguish within Him. (It would be reasonable to assume that God Himself was having to endure similar anguish as He withdrew Himself from His Only Begotten Son.)
The beatings, abuse and crucifixion that Christ endured, were of no consequence. They only served to demonstrate to the universe how evil sin really was and how it would affect mankind to the point that they would seek to destroy the innocent Son of God.
As Jesus hung on the cross He could no longer sense God's presence and He cried in anguish, "My God, My God! Why have you forsaken me?".
At the end, Jesus willingly gave up His Spirit(Breath of Life)...See Matt 27:50 & Luke 23:46. This "Breath of Life" that comes only from God, returned to God and Jesus died.
The Separation from God was complete.
It is this same separation that the Wicked will experience in the end.
Pretty simple isn't it.