Is the Devil omnipresent:

Scripture never suggests the devil is omnipresent. Generally, people believe the devil is omnipresent only because they believe the devil tempts all people at all times. Such an attack would necessitate omnipresent qualities. However, while the devil himself does tempt people, he commands a large army of fallen angels (or demons). Between himself and the demons he commands, it is reasonable to believe he can tempt all people at all times without being omnipresent.

Submit yourselves, then, to God. Resist the devil, and he will flee from you.

James 4:7