Why was Jesus forsaken?

About the ninth hour Jesus cried out with a loud voice, saying, “ELI, ELI, LAMA SABACHTHANI?” that is, “MY GOD, MY GOD, WHY HAVE YOU FORSAKEN ME?”  And some of those who were standing there, when they heard it, began saying, “This man is calling for Elijah.”  Immediately one of them ran, and taking a sponge, he filled it with sour wine and put it on a reed, and gave Him a drink.  But the rest of them said, “Let us see whether Elijah will come to save Him.”  And Jesus cried out again with a loud voice, and yielded up His spirit. (Matthew 27:46-50)

This happened at the crucifixion, and the gospel of John says,

Therefore when Jesus had received the sour wine, He said, “It is finished!” And He bowed His head and gave up His spirit. (John 19:30)

In David’s address about the temple in 1 Chronicles 28:20 it says,

Then David said to his son Solomon, “Be strong and courageous, and act; do not fear nor be dismayed, for the LORD God, my God, is with you. He will not fail you nor forsake you until all the work for the service of the house of the LORD is finished.

God forsook Jesus because all the work for the service of the house of the LORD was finished.

References

Matthew 27:46-50

John 19:30

1 Chronicles 28:20

Philippians 2:9-11

Ephesians 2:19-22