But I do know that Aquinas taught that an angel could travel any distance in an instant. So a demon whispering in your ear could come and whisper in mine instantly.
As far as I know Satan himself isn’t the primary tempter for every person… so I don’t think he needs to be outside of time to “get all his work done” … there are the billions of demons under him doing his work. But I really don’t know about whether the devil is outside of time
I actually believe the answer is no. I don’t think he is omnipresent like God is. But he does have many demons who can tempt two people simultaneously
There’s a story in the Russian tradition about a monk who became clairvoyant. His abbot wanted to test if this came from God or from a demon, so he asked the monk, “Where is [random person] right now?” The Abbot reckoned that if the power came from God, the monk would know the answer immediately because God is everywhere. But if the monk took a moment to answer, it meant the demon was traveling around looking for the person, and so the monk needed exorcism. (But this isn’t dogma, of course.)
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