“We either choose God or we choose Satan”—wrong. G-d created satan, there is no equal status. this is a pagan concept...We have the ability to choose good over evil, as evil is crouching at the door. G-d has allowed us that choice. But do not be deceived, satan has no equal status with the G-d of Abraham, Issach and Jacob.
"Similar titles are found elsewhere in Scripture concerning Satan. Satan is called the "prince of the power of the air" in Ephesians 2:2. He is called the "ruler of this world" in John 12:31. These titles, and many more attributed to Satan throughout Scripture, signify his capabilities. To say, for example, that Satan is the "prince of the power of the air" is to signify that in some way he rules over the world and the people in it."
"This is not to say that he rules the world completely; only God does this. But it does mean that God, in His infinite wisdom, has allowed Satan to operate in this world (within the boundaries God has set for him) and has allowed Satan to operate with an agenda. When the Bible says Satan has power over the world, it must be made clear that God has given him domain over unbelievers alone. Believers are no longer under the rule of Satan (Colossians 1:13). Unbelievers, on the other hand, are caught "in the snare of the devil" (2 Timothy 2:26), lie in the "power of the evil one" (1 John 5:19), and are in bondage to Satan (Ephesians 2:2)."
"So, when the Bible says that Satan is the "god of this world," it is not saying that he has ultimate authority. It is conveying the idea that Satan rules over the unbelieving world in a specific way. In the case of 2 Corinthians 4:4, the unbeliever follows Satan's agenda. According to 2 Corinthians 4:4, the "god of this world has blinded the minds of unbelievers, so that they cannot see the light of the gospel of the glory of Christ." Satan's agenda includes pushing a false philosophy onto the unbelieving world—a false philosophy that blinds the unbeliever from the truth of the Gospel. Satan’s philosophies are the fortresses in which people are imprisoned, needing to be set free and brought captive to Christ in obedience to the truth."
http://www.gotquestions.org/Satan-god-world.html
So, according to God, unbelievers, by virtue of the fact that they have rejected the only Person Who can give them access to the Father, are by default under the dominion of Satan.
Not a pagan concept at all, but a very Biblical one.
You hit the nail on the head. It is pagan.