What do you think saying God's name in vain, really means?

Now adays Sunday schools teaches kids that they shouldn't say things like "Jesus Christ!" or "God damn" and that kind of thing. But my world religion professor said that when that commandment was established, it meant purely that we should not utter God's name literally out loud. Since catholics believe that Jesus Christ is God, we cannot say Jesus Christ out loud. But God is ok because it is a "title" rather than a true name. This is more true for the Muslims and the Jewish community because they don't have God's real name at all I think. Allah only means God in english and the Jews have YHWH which in english means "I am". They don't even say this out loud. And the reason or the concept behind this is because God, no matter what the religion, is higher than any humans and therefore to respect him, we can't say his name--to show that we are of lower status than he is.