How many agree that if you never read about something or told about it then it doesn't exist?

no muslims here has ever read about the moon god ,allah, that was worshiped from spain to the nile for thousands of years. according to muslims here allah, the moon god, doesn't exist because they have never read about him or been told about the pagan moon god, allah. so how many agree if you have never read about something or told about it it must not exist? should all books and clay tablets be destroyed that tell about the moon god,allah.