God... Truth or fiction?

Well, I wouldn't say that. People readily converted to other religions. Entire states converted. The Persians, for example, adopted Zoroastrianism instead of their traditional polytheistic religion. And the reform was led by the king himself. You know, the powerful of this world were not very concerned with higher matters even then. Or, for example, the first attempt to adopt monotheism was in Ancient Egypt. The pharaoh wanted to replace the traditional worship of Osiris and Ra with the worship of the solar disk Aten. He didn't care what Anubis would do to him.