Why did Jesus say, “My God my God why have you forsaken me”?

The reason Jesus would say this (Matt. 27:46) is that He was a man as well as divine, and as a man, He was made under The Law (Galatians 4:4) and for a while lower than the angels (Hebrews 2:9). People sometimes don’t realize that Jesus, being a man under the law, would have someone He would call God, someone He would worship, etc., because He is under The Law. The law required worshiping God and praying to Him.

Again, Jesus has two distinct natures, the divine, and human. We call this the hypostatic union, and it is exemplified in verses like the following.

• John 1:1, 14, “In the beginning was the word, and the word was with God and the Word was God… 14, and the Word became flesh and dwelt among us…”
• Colossians 2:9, “for in Him dwells all the fullness of deity in bodily form.”
• Hebrews 1:8, “but of the son, he says, ‘Your throne, O God, is forever and ever.'”