I'm a Catholic by religion and it states in the Ten Commandments that one must not use the name of the lord God in vain. I would like to know when people started saying phrases such as those aforementioned, also what made people think it was normal to say them and if the Catholic Church still deems it as a sin.
Characters in Plato's dialogues use phrases like "by Zeus," or "by the gods" as ways of emphasizing points. (I'm most familiar with the Republic, but others contain similar oaths used as interjections).