It is true that the Devil influences many people to sin, this might not always be him directly, but instead, an indirect result of his already established work in the world.
How, biblically, should we think of God's omnipresence? The word means that God knows exhaustively, and upholds and touches continually, every single item in the universe he has made, from the tiniest genes and electrons to the most massive stars in the expanding universe to the most complex mind-body interactions in the psyche of over 6 billion people. God is here, there, and everywhere, and his mind and hand are on everything. We are never out of his sight (Psalm 139), and we cannot get away from him (John 1). Wherever we are, he is there too. This is not simply a matter of transcending spatial confines. Strictly speaking, God has no spatial location at all, for space belongs to the created order and exists in him rather than he in it. Such is the omnipresence of God. (Packer, http://www.christianitytoday.com/ct/2000/september4/36.115.html)
- (Job 1:6-7) “Now there was a day when the sons of God came to present themselves before the LORD, and Satan also came among them. The LORD said to Satan, “From where do you come?” Then Satan answered the LORD and said, “From roaming about on the earth and walking around on it.”
- (Matthew 4:3) “And the tempter came and said to Him...”
“It was revealed to them that they were not serving themselves, but you, in these things which now have been announced to you through those who preached the gospel to you by the Holy Spirit sent from heaven-- things into which angels long to look” (1 Peter 1:12).
"And angels who did not keep their own domain, but abandoned their proper abode, He has kept in eternal bonds under darkness for the judgment of the great day, just as Sodom and Gomorrah and the cities around them, since they in the same way as these indulged in gross immorality and went after strange flesh, are exhibited as an example in undergoing the punishment of eternal fire" (Jude 6-7).