Here again, we need to understand that  Jesus was born and lived on this earth as a complete man, laying aside His equality with God and lowering himself to the form of a man. The way Jesus addressed here is noteworthy “My God” is what Jesus called. Before this, never has Jesus addressed as ‘God’, instead He called ‘Father’ always.

The cry of Jesus on the cross is the cry of a sin-bearer, representing all sinful men, abandoned by God and separated from communion with God.  Jesus who was without sin was made to be a sin, on behalf of the sins of all mankind.

Jesus was fully man, except for sin. Jesus was born without sin, to be a penalty for the sins of man. Jesus being a penalty for the sins became sin and was separated from God, as man. “God made him who had no sin to be sin for us so that in him we might become the righteousness of God” 2 Corinthians 5:21

So Jesus having borne our sins, and becoming sin having been separated from God; today through the blood of Christ and His righteousness, we can come near to God. Hebrews 10:19

Jesus having called His Father, God, today we can boldly call God,’ our Father ‘.                                                                                        Galatians 4:6-7 “Because you are His sons, God sent the Spirit of his Son into our hearts, the Spirit who calls out, "Abba, Father." So you are no longer a slave, but a son;