The Old Testament not only tells the history of the nation of Israel, but also contains visual-aids both for the Israelites and for us to help us to understand what God is like.
The ceremonial laws are a case in point.
Just reading through them, there are so many ways that the people could become “ceremonially unclean”, and so many steps to perform to become “clean”.
Only the high priest could only enter the “Holy of Holies” once a year, and that only after a sacrifice.
Touching the Ark of the Covenant could result in death, unless you were properly appointed as a priest.
All of these spoke of the “separateness” of God and the purity of his holiness.
The things of God could not be mixed in with the grime of everyday things because they were fundamentally incompatible.
To further underline the seriousness of this was the requirement for animal sacrifices, but this was also a visual-aid, pointing us to Jesus and His sacrifice.
What all this serves to illustrate, is the situation in which we find ourselves.
We are sinners, and God is utterly holy.
Would contact between God and us contaminate God? Or would it instead destroy us?
We are finite creatures, and God is the infinite creator, so I think I know which it would be.
So, what happened when Jesus became human and lived among us?
He allowed Himself to come into contact with the grime of everyday life, whilst remaining pure, and on the cross identified Himself with us to the point of carrying our sin for us, so that we would not be destroyed by the holiness of God.
This is the length to which God went to save us.