Catholic Church Statement on Fallen Angels (Demons)
"These beings, because of pride, did not return God's love. God did not destroy them, but permits
them a limited scope of activity. Their condition is permanent for no creature can turn away from the perfect good of the
beatific vision once he has come to enjoy it, and no additional reflection could change the mind of a purely spiritual being
who has turned away."
[Source: Catholic Online - Angels]