An interesting title ascribed to Satan is "the god of this world". One could hardly imagine the Lord, who accepts no blasphemy, could ever actually call Satan the "god of this world". And yet, this is what the word of God does call him. Why?
Just as Christians today use the word "god" to describe something other than God (for example, Allah is still a god), so also does the word "god" not always mean Lord in the Bible. There are many things the Bible calls, or compares to gods, which is translated with a lower case g.
This actually includes human beings. Moses was told that he was to be as God to Aaron (Exodus 4:16), and in John 10:34-36, Jesus pointed out that since the Old Testament refers to those to whom God gave His word as "gods", it is entirely legitimate for Him to refer to Himself as the Son of God. Psalm 86:8 and Psalm 97:9 both exalt the Lord above "all other gods", especially with regard to His works and His status above the earth. Not a single one of these verses legitimises any other being, real or imagined, as an actual contender for God's throne, but rather describes them based on an attribute, whether it be legitimate or usurped, that they nevertheless possess.
Which leads us to the question, what is it about Satan that enables him to receive the lofty title of "the god of this age"? The same thing that enabled Moses to receive that same title over Aaron. As Moses was given authority, so also has Satan been given authority.
In Luke 4:6-7, we see exactly how much authority Satan has. "And the devil said to Him, “All this authority I will give You, and their glory; for this has been delivered to me, and I give it to whomever I wish. Therefore, if You will worship before me, all will be Yours.”" The entire Roman world, everything that could be seen from the top of that mountain, was under the authority of Satan. And in Revelation 2:13, we see that the Church in Pergamos is located "...where Satan’s throne is".
That Satan is the "god of this age", then, does not refer to Satan being above, or even equal to God. Quite the opposite, Satan's power is entirely predicated on the God who created him. Satan can do nothing that is not permitted by the Lord. We actually see this in the book of Job, wherein Satan must receive permission to test Job, and may do nothing to Job that the Lord does not permit.
This is both an encouraging thought and a worrying one. On the one hand, if Satan can do nothing without the Lord's permission, the only bad things that will ever happen will ultimately lead to good. On the other hand, is it not a little disconcerting that the Lord would actually grant the world's most famous villain so much power? After all, we are not just talking about giving him the ability to oppress one man here. God has actually given Satan the power to control the world's philosophies, even to the point where he can put anyone he likes in a position of power, or worse, actually blind men to the Gospel.
These are some very difficult questions. Questions I don't even believe we have the right to receive an answer to. After all, as the Lord said to Isaiah, "For as the heavens are higher than the earth, So are My ways higher than your ways, And My thoughts than your thoughts." (55:9). Could we even begin to understand why God would do this?
But here's what we can understand. As much power as Satan has, he actually has none. How many unbelievers come to Christ? The worst of sinners, including Paul, have come to know Him, and Satan could do nothing about it. Every human being that will ever go to Hell deserves it. It's not like they deserved Heaven, and yet somehow Satan managed to wrestle them from Jesus' hands. In fact, as important a role as Satan plays, it is equally important to note that man does not exactly resist him. In some ways, we could even suggest that he is insignificant.
In Genesis 8:21, we are told that the imagination of man's heart is evil from his youth. Jeremiah 17:9 tells us that the heart is deceitful above all things, and desperately wicked. Biblically speaking, Satan is given no credit for man's sin. Or, as my old friend put it, it's not like Satan is making us do evil things, but rather we keep going back to him for new ideas. Those who are in Satan's power are in it of their own free will. They didn't want God, and so God left them (Romans 1:28-32).
But what's especially interesting is that even in all of this there is grace. For God to give a man over to Satan is often an attempt to draw that man to God. In 1 Corinthians 5, for example, we read an example of a man whose sexual immorality was beyond unacceptable, even in the surrounding secular culture. Paul's command: "deliver such a one to Satan for the destruction of the flesh, that his spirit may be saved in the day of the Lord Jesus." (v5).
Satan is, indisputably, the ultimate bad guy. He deserves no thanks, no love, and no glory. A time will come when his many evils will be repaid, his previous beauty will be replaced with scrawniness, and Hell will be his eternal residence, not as a king, but as the lowest of the wretches who suffer there. But God knows how to use even him for His glorious purposes. The "god of this age" is just one more tool to glorify the God of Heaven.