Both ancient and modern history have shown what ultimately happens to widely believed yet mistaken concepts. Absolute facts slowly erode them until they finally crumble.
In ancient Greece, for instance, it was generally thought that Mount Olympus was inhabited by gods with names like Zeus, Athena, and Apollo. Suppose, just for fun, you could somehow travel back in time to ancient Athens. Imagine speaking with people there who believed that these gods not only were real but actually governed daily events. If you tried to explain to them that the gods were just myths, you’d likely be ridiculed, or worse.
And then, what if you went so far as to introduce the concept of God as a single divine Spirit? You would probably get an argument like this: “The gods of Olympus must exist! All my friends talk about them every day. I see statues of them everywhere. So many people can’t be wrong! Why should I believe what you say when every person I know thinks so differently from you?”