Because of God's perfection in righteousness, he is so perfect he has no flaws that God Almighty has no reason to diminish himself to be around sin.
Why should he? To please us?
God has no debt to pay us. owes us nothing, since it is quite the opposite.
It is our job to believe, not his job to continually prove himself.
We have sin in us still simply by being human until we are perfected, after resurrection.
We are told that like a silversmith he refines us.
This is done with fire, I view that as trials when trusting him him purge the impurities and sin from us.
We are also told after Jesus came we would then be baptized in the holy spirit,
and with fire.
again purging sin and impurities from us to be more in the likeness of our Lord.
What if God revealed himself fully in all his glory? All that purging of sin at once happening?
Perhaps that's why some people spontaneously combust, who knows.
But also because he is the destroyer, (destroyer of sin) we would most surely die for having any sin within us while in his presence.
1 Cor 10:10
And do not complain as some of them did, and were killed by the destroyer.
He didn't even fully reveal himself to Moses. Just his backside.
But we can rejoice to be content God has evidenced himself through all his creation.
Romans 1:20
For since the creation of the world God's invisible qualities--his eternal power and divine nature--have been clearly seen, being understood from what has been made, so that people are without excuse.