Why do people not believe in the Lord?

Answer 1

For various reasons. But it mostly boils down to the rebelliousness in nature that we are all born with. The flesh naturally wants to rebel against its Creator. We all are given free-wills, so we have to each choose for ourselves what we accept. And some choose to not accept Christ. Most people growing up are indoctrinated with the religion of their parents, without ever thinking for themselves or being exposed to other religions. Asking "Why do people not believe in the Lord" is the same as asking "Why do people not believe in Thor, the viking god of thunder?" Each deity is likely to exist as another. When you don't see the Greek god Ares stomping around helping out with wars, or , you shouldn't be surprised of the notion that the christian god doesn't exist either.

Many civilizations have their own creation story, along with their own god or gods. When you take a moment and think about it, it becomes logical to doubt that the god from your creation story is the true god. You might think some people are atheists for not believing in your lord, but since you are not believing in Greek, Norse, Hindu etc gods, you are just as much an atheist.