Egyptian as a Holy Language

I imagine we're all familiar with the concept of a magical or holy language -- that it is a good language for addressing the gods or other forces and powers one wishes to speak to (for a fictional example, see the Old Speech in Ursula K. LeGuin's Earthsea series). Aramaic functioned that way even in Antiquity, and Egyptian had started to: in Greek accounts hieroglyphs (see the name itself) had already begun to acquire the mystical connotations they still enjoy, today.

Does Coptic have any of this luster? What does or does not contribute to it?

What begins such a notion: the loss of the language or writing system? Age? Characters versus alphabets? Inherent niftyness? Do other undeciphered (or formerly undeciphered) languages have the same aura?

-Kushana
P.S. In line with the famous anecdote about the Greek spell for catching fish not working on a famous scholar's fishing trip, I am here to report that the Coptic spell for getting rid of rats, alas, left something to be desired.