I was given a question that I really don't know how to answer or at least the young man doesn't want to accept my answer. His question was: "When Jesus was dying on the cross and called out Father why have you forsaken me, how could Jesus be God at this time?" Please help me try to satisfy this young man's mind to the point that he will let go of this issue and go on trying to please God by obeying His Word. Thank you.
If a person's mind is set on not believing, there isn't anything you or I can do. "And for this reason God will send them strong delusion, that they should believe the lie, that they all may be condemned who did not believe the truth but had pleasure in unrighteousness" (II Thessalonians 2:11-12). That is not to say you shouldn't try, but if you keep running up against a brick wall, eventually you will need to move on.
If a child really irritates his father, to the point his father declares, "That's it! I've had enough of you. You are no longer a part of this family!" Does that change who the child is? Has is his biological nature change so he is no longer related to his dad? Does his DNA change?
The question asked assumes that Godhood is something that can be taken off and put back on. The Bible teaches: "In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things were made through Him, and without Him nothing was made that was made. ... And the Word became flesh and dwelt among us, and we beheld His glory, the glory as of the only begotten of the Father, full of grace and truth" (John 1:1-3, 14). "Only begotten" is an important word here. It means something that is one of a kind. It is say that Jesus is uniquely of the same kind of being as the Father. Or as Paul put it, "For in Him dwells all the fullness of the Godhead bodily" (Colossians 2:9). Jesus could not stop being deity any more than I can stop being a human.
Now Jesus did leave his position of glory as God to take on human form, but that didn't make him any less God. "Let this mind be in you which was also in Christ Jesus, who, being in the form of God, did not consider it robbery to be equal with God, but made Himself of no reputation, taking the form of a bondservant, and coming in the likeness of men" (Philippians 2:5-7). See "Is Jesus God?" for more on this topic.
In regards to Jesus' statement on the cross, many people misunderstand what Jesus was saying. See "Did God forsake Jesus on the cross?" It doesn't say God rejected Jesus, as so many seem to claim.