Q. Why does God let the devil and others continue to do bad things?
The question of why God allows the devil to continue affecting evil in the world is a hindrance of belief for many people. With such a difficult question, I like to illustrate my understanding this way: Let's say you were going to have a child.
Now before you had that child, do you get any kind of written agreement from the government or your spouse that the child would always be obedient and complacent and a good child? Of course not.
You are also aware that this child may give you some difficult times and misbehave. So why would you have that child? Well, most people want children so they can share their love. As it is natural for us to have children, it is natural for God's character to create. And of course, love involves risk, because you cannot force someone to love you. You can force obedience and even fear, but you can't make someone love you.
So there's risk that love will not be reciprocal. Sometimes when we love people, they don't love us back. God, because when Adam and Eve rebelled against Him, had to take a risk. He created these creatures with a will, and He allows them to live out their existence as they choose. There is a time when He will cut it off because the problem of sin will only get worse, but He is a God of love, and He gives His intelligent creatures free will.