Have you ever really looked into it? The clear teaching in the bible is the fact that Christ was forsaken(separated) by His Father when He had the sins of the world laid upon Him. The Father cannot look upon sin. We are in a spiritual battle, and In spiritual death before we believe.
If it was His physical death and blood that paid for our sins, The Father would have just killed Him on the alter, like the animals in the OT.
Psalm 22:1~~
New American Standard Bible
For the choir director; upon Aijeleth Hashshahar. A Psalm of David. My God, my God(Note: not "Father"), why have You forsaken me? Far from my deliverance are the words of my groaning.
Matt 27:46~~
New American Standard Bible
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?"
Matt 27:45~~
New American Standard Bible
Now from the sixth hour darkness fell upon all the land until the ninth hour.
From noon to three there was darkness on all the land. This is when Jesus had the sins of the world laid upon Him and the Father Judged those sins........It was Jesus Christs substitutionary spiritual death that paid for our sins. He was separated From the Father.
When He said ,"It is finished." He was still alive and had a lot of blood left in Him.
John 19:30~~
New American Standard Bible
Therefore when Jesus had received the sour wine, He said, "It is finished!" And He bowed His head and gave up His spirit.
John 19:34~~
New American Standard Bible
But one of the soldiers pierced His side with a spear, and immediately blood and water came out.
His Spiritual death paid for sins. His Physical death brings our bodily resurrection.