This blog post will probably be nothing short of blasphemous to most people, but I think it's a fun thought.
So assuming you believe in Christianity (specifically Mormonism) the kind of general story is that Satan has to tempt us so we can prove our worthiness. The Mormon story goes that Satan had a plan to force us to all be perfect so we could return to heaven and worship him for saving us then Jesus was like no, you all can go make your own choices and if you decide to accept me I'll be punished for you and you can come back and worship God. Meanwhile Satan gets kicked out and decides he wants to screw with our heads and tempt us to do wrong things to get as many people to come live with him in "hell" instead of with God in "heaven."
Satan sounds like a pretty bad dude at this point. What has to be considered though is that for Christ's plan to even exist, Satan must exist. Satan is what creates evil, the required antagonistic force in Christ's plan. He's what tempts us to do wrong and sin as to not go back to Christ and God, but he is completely necessary.
So did Christ and God banish him for the sake of having an element of evil? It almost sounds like had we just gone with "Satan's plan" there would have never been evil, he wouldn't have been "forcing" us to be good, there just wouldn't have been any evil to participate in. However when God denied him permission because of his arrogance in wanting the glory of a people who he didn't create evil was created at this point. This became part of Christ's plan. Satan was needed in it. Without Satan, Christ wouldn't need to be our savior.
Why does Satan get such a bad reputation then? He's just a misunderstood and incredibly arrogant individual (assuming he even exists) who made a bad choice. We should feel sorry for the guy and help him if we want to be "Christ-like," right? Also what would life be without temptation? Some of the greatest feelings in the world come from either overcoming temptation or temptation itself and without it we would never be able to prove ourselves to God to be rewarded with whatever he deems us worthy for.
This has further implications though. Satan isn't the cause of all evil is he? If a hurricane happens and kills some people is that Satan's doing or is that just natural evil? If you answer that it's Satan's doing then you have to accept that Satan helped create the universe which means he has powers similar to what we know of God. If you say that this was not Satan's doing then you have to accept that God created a universe with built in evil. If God is capable of creating evil, then would this not mean he has to have an understanding and desire for it? Furthermore, God created Satan, according to LDS beliefs. God created Satan, who is the father of all evil, so God did create evil, or maybe he just messed up a little in the whole creation of beings and some of them (a third according to Mormonism) came out wrong.
My mind just went spiraling off on a new tangent. I have to study for finals, I'm done thinking about this.