Even the bad guys have a purpose in God’s scheme.
How have I come to that ridiculous conclusion? Well, in the Bible when God speaks to Pharoah through Moses, He pretty much tells him that, though Pharoah has thought all along that he was in control, God has been using him for His own purpose, that He might be glorified. You can read the exact quote here.
Now, we obviously can’t know exactly how the bad guys fit into the big picture until God reveals it, as He has done here. Like, what was the purpose of Hitler? And Osama bin Laden? Somehow, God is going to use even what they (and other bad people) have done for His glory. It’s just hard for us to see how right now.
And, lest we begin to feel grand about our holy selves, consider that the sins of the worst people in history are just as much sins as the “little” ones that we commit day by day. When compared to a truly holy and perfect God, even our best deeds are ugly.
The good news is, if God uses the bad guys for His purposes, then chances are that He’s using you and me, too. After all, we were created to give God glory. It’s just better for you when you do it on purpose.