==Correct and True Etymology of English words "Myth, Mythology"==
Greek μυθολογια "legend, storytelling" is derived from μυθος "speech, thought, story, myth", itself of unknown origin. English mythology is in use since the 15th century, in the meaning "an exposition of myths". The current meaning of "body of myths" itself dates to 1781 (OED). The adjective mythical dates to 1678; English use of myth is later, first attested in 1830, in its original English meaning of "untrue story":

"These two stories are very good illustrations of the origin of myths, by means of which, even the most natural sentiment is traced to its cause in the circumstances of fabulous history." Westminster Review 12:44 (1830)

This is the earliest known usage of "myth" in English. In case anyone didn't know, in 1830 English "fabulous" doesn't mean "wonderfully aesthetic", it is the adjectival form of "fable", that is referring to a fantasy or fairytale.  In 1830 the term "myth" was new, so it carries what we call a gloss, things "by means of which even the most natural sentiment is traced to its cause in the circumstances of fabulous (i.e., fictional) history.".  This was not only the original use of the word, but the original academic use of the word, note the source, Westminster Review. That is still the way most all people define "myth" today.  It's for reasons like this, that Wikipedia is so notorious for its mental disconnect with mainstream thought, and its enforced use of its own internal terminology / jargon, or to put it less nicely, doublespeak.  (ውይይት) 

In 2005, a single-purpose account added "mythology categories" to a wide range of articles including Death and Resurrection of Jesus, Virgin Birth, and Transubstantiation, creating a huge uproar.  The outcome of the discussions then was overwhelmingly to reject the categories as imflammatory and inappropriate.  It was agreed at that time that theological and scriptural articles do not fall into the category of "mythology" and today, none of these articles are so categorised, apart from Noah's Ark.  

Just last month, WP:RELIGION undertook to move the article "Yoruba mythology" to Yoruba religion.  This is because the term "mythology" is held to be demeaning, because Yoruba religion is still practised today, and the Yoruba who practice it constitute a significant viewpoint.    It is indeed regrettable that so much resistance is facing the prospect of extending the same consideration to the canonical Book of Genesis.  The Churches have drawn the line by indicating which books they consider canonical, inspired texts.  Genesis is among them with no exceptions as far as I know. What gives Wikipedia the right to draw the line so as to exclude other Biblical Books from "mythology", but include the stories of Genesis?  No books that are considered sacred scripture by ANY large religion of today should be portrayed as "mythology".  That's simple common sense.  We shouldn't call the Quran "mythology" either, we shouldn't call anyone's sacred books widely adhered to today "mythology".    (ውይይት) 

Now things like Hesiod and Orpheus are another story, I think the reason Hesiod and Orpheus have conventionally been referred to as "mythology" for some time is because no significant numbers of people have ever come forward claiming to believe these books to be historical or literally true since the year 400.  At least I will go out on a limb and say I don't know of any, not a single one. Correct me if I'm wrong, but I think it's pretty safe to say they have been discarded, and nobody objects to the conventional use of "mythology" for these.  But please realize that this is not the case with Christian, Muslim or Bahai writings, nor indeed the writings of many other living religions.  (ውይይት)