Do you mean why do I believe Jesus Died on the cross like a really physical death. Some people don’t believe he really died. He drank drugged wine and was not really dead… physically. If you have ever been deer hunting and have shot a deer with an arrow and the animal looses a significant amount of blood—it’s not long before it is dead. The soldier pierced Jesus with a lance and blood and water gushed out… He died on that cross!
But if you’re asking why did He die? I was thinking about this today. Here was Adam and Eve. They messed up. I bet they were sorry but there was nothing they could do to make atonement. I bet they tried. I bet their children tried. Able was making offerings to the Lord… I know Moses and the Israelites tried because they had sacrifices of atonement. And here was God, knowing they would try many different sacrifices. Sometimes animals, plants, children…
God even asked Abraham “would you sacrifice your dearly beloved son to me?” God already knew that none of these offerings would make atonement. It had to be a God-man. Only one could do the sacrifice… Jesus.