The Bible says that God has an enemy: Satan (Revelation 12:9). Oftentimes this enemy is attributed inventive abilities that run counter to biblical teaching. Therefore it is important to have an accurate understanding of Satan, his origin, and ultimate limitations as an originated being.
One of the false notions of Satan is that he is coeternal with God and possesses an equal balance to His power. This is known as “ethico-religious dualism” which, “… asserts that there are two mutually hostile forces or beings in the world, the one being the source of all good, the other the source of all evil.” Implied in the phrase “mutually hostile forces” is the notion of both entities having equal strength. Therefore, whatever God is (eternal, omniscient, and omnipresent) Satan must be as well.
Practical religious applications to this view can be seen in both the Manichaeistic and Catharist sects. Both held to a supernatural battle (Manichaeists characterized it as Light vs. Darkness) that has been waged for all eternity. However, these particular worldviews lead to false doctrine. For example, Manichaeists believed, “… in the imprisonment of Light particles in plant, animal, and human life.” Since human beings contain Light (or good), they must therefore be, “… one in substance with God.” Catharists believed that, since the world was created by evil spirits and that matter was inherently evil, the creation itself was not “good” (Genesis 1:31) and that, “… redemption involved the rescue of the human spirit from the bondage of matter…”
In order for ethico-religious dualism to have any merit, many passages of Scripture must be ignored about the true nature of Satan and his conflict with God. The Bible says that Satan is not an eternal being but was created by God (Ezekiel 28:15) and is not equal in power to Him but wished to be (Isaiah 14:12-15). So he rebelled and was cast down to earth (Revelation 12:7-9) where he is allowed to defy the Lord but only in a limited capacity (Matthew 12:29; Ephesians 2:2).
There are theologians that do not accept the Ezekiel 28 and Isaiah 14 passages (I listed above) as descriptions of Satan because both prophets appear to be talking about the kings of Babylon and Tyre. While I do find this argument to be compelling, other passages in Scripture seem to dovetail with this notion of Satan as a rebellious angel (Job 1:6; Revelation 12:7-8). Also, there is a, “… close connection Satan has in Scripture with the government of the satanic world system… of which both ancient Babylon and Tyre were an inseparable part.” Therefore, I’m inclined to accept the Ezekiel and Isaiah passages as legitimate descriptions of Satan.
Because Satan was a created being and he is the supreme purveyor of evil in the world it could be said that God is the ultimate source of evil. But, in order for this assertion to be true, one must assume that God created Satan, specifically, to be evil. But Ezekiel 28 describes God’s original intention for Satan as “full of wisdom”, “perfect in beauty”, and “blameless” in his ways. It was Satan’s free choice to become evil therefore God is not to blame for evil in the world.
The story of Job provides several inferences to the limitations of Satan. He is accountable to God (1:6), he is not omnipresent (1:7), he is not omniscient (1:8), and he cannot do anything without God’s express permission (1:12; 2:6). Therefore, one cannot simply blame Satan when he yields to temptation because, at best, Satan’s power is merely relegated to external influences. “Unlike the Holy Spirit who can influence believers’ minds directly, angels are limited to external impulses.” Satan, as an angel, therefore cannot be blamed for one’s sin.
Satan as a created, limited, and inferior being to God is not some coeternal, coequal force that the Manichaeists or Catharists would believe. Various passages in Scripture tell of the real Satan who fell from Heaven because of his wickedness and, while openly wages rebellion against the Lord, cannot do a thing without His permission. In order for Christians to fully comprehend God’s enemy, they must not dismiss (partially or otherwise) the only record they have of him – which is Scripture.
 Kuhn, H.B., “Dualism.” in Evangelical Dictionary of Theology, ed. Walter A. Elwell, 2nd ed., 357. Grand Rapids, MI: Baker, 2001
 Hoffecker, W.A., “Manichaeism.” in Evangelical Dictionary of Theology, ed. Walter A. Elwell, 2nd ed., 729. Grand Rapids, MI: Baker, 2001
 Oliver Jr., O.G., “Cathari.” in Evangelical Dictionary of Theology, ed. Walter A. Elwell, 2nd ed., 214. Grand Rapids, MI: Baker 2001
 Unger, M.F., “Satan.” in Evangelical Dictionary of Theology, ed. Walter A. Elwell, 2nd ed., 1054. Grand Rapids, MI: Baker 2001
 Towns, Elmer, Theology For Today, 2nd ed. (Mason: Cengage Learning, 2008), 347.