Question: Why God doesn’t just destroy Satan now and do away with evil?
Let me first say that your question is presupposing that getting rid of Satan would be the solution, as if he were the source of all evil. Let’s say God were to get rid of Satan tomorrow…what would change? If Satan is the reason we sin and the reason for the existence of evil, then how are we to be held morally accountable for our own actions as the bible clearly teaches? Seeing how the Bible does not teach that Satan is the source of evil, it is therefore not a view that we, as believers, should hold to. Now if your question is begging a much deeper question like, “Why has God not yet done away with evil?” Then I would have to say this too is equally underlined with a mistaken presupposition. The reason being is that this makes evil out to be some abstract “thing” that exist and needs to be done away with.
We must first understand just what kind of thing evil is. To be brief, it can be said that evil is a deviation from the good. Hence, evil is a lack of something, not a something in itself. Much like hunger is not something that can be done away with by “removing” hunger, but rather, the appetite must be satisfied to rid the self of being hungry. Similarly, if evil is done, not merely by Satan, but people, then it follows that evil is something that is freely chosen and hence, cannot be “removed” in the same sense that hunger cannot be done away with. If we are to remove hunger, we must add food. And if we are to remove evil, we must add good (which encompasses God). It is therefore not God’s job to do this, but ours.
One more thing can be said concerning evils existence. It is erroneously believed that God will one day “destroy” evil and yet, that is not the correct theological view. So it’s not that God will one day destroy evil, but rather, that God will one day quarantine evil. This is the Biblical definition of the “second death”. A total separation from God. Thus, evil (a lack of good) isn’t something that can be “destroyed”, but it can be quarantined. Those who have made their free decision to be separated from God will have their wishes respected and granted. As CS Lewis said regarding this issue, “what could be more fair but for God to give them what they want?”
That being said, if we want to rid the world of evil, we have to either rid the world of people or get people to stop doing evil and do good. This however, is not something that God could force on people. If people are to be free, then they must make free decisions to choose God and choose good. But the ability to choose good also comes with the ability to not choose good and to further choose evil. So in conclusion, if anyone is to blame for the evil in world, we need to look no further than the mirror in front of us.