A magic word that was interpreted as "let it be" in Hebrew, and used to evoke divine response to a prayer. Such words frequently began as names of deities. Perhaps this may have originally invoked the Egyptian god Amun, "the Hidden One"—the sun in the belly of the Mother before sunrise. Its hieroglyphic symbol meant pregnant belly. (Author footnote, Book of the Dead, 194)
Also, Amen is from the Hebrew meaning "certainly" or "truly," and is an expression used in worship by Jews and Christians, and to a lesser extent by Muslims. When uttered at the end of a prayer it means "So be it," so to express an affirmation of belief. When said after a Creed, the same affirmation is expressed. A.G.H.