Jesus died innocent so we could share His death, even though we are guilty. Like being in the ark. The flood destroys all that is outside the ark (judgment unto death), those inside the ark are safe, and come through this rain of death to a new life in a cleansed world.
If Jesus were not innocent He would not have "survived" His death, He would have been dead because He sinned just like everyone else. Since He had no sin there was no power of death over Him, He is our ark.
We are baptized into Him, into His death. We share His death, like being in the ark, so we can share His new life after the judgment passes.
Concerning holiness (set apart for God's purpose), sharing in Jesus' death sets us apart for God, though we are still in need of renewing. The renewing of the mind is the process in which God brings that separation He induced by joining us to Jesus in His death into our daily behavior, our thoughts and words and actions.
An example would be a priest needs an implement for the temple service, say a shovel for clearing out the altar. The only one available is bent, and he needs it, so he claims it for the temple, and that makes it holy. Still, it's bent, so it doesn't work well. As time goes on, he cleans it, straightens it, an now it both looks and acts holy, but in point of fact, it was made holy when it was claimed for the temple.
It's the same with you.
Much love!
