Er, sorry there but Egyptian beliefs existed long before either the Roman or the Greek belief systems.
Egyptian belief system have been dated back to at least 3,000 years B.C.E.

As someone mentioned earlier, Jewish people were the first to firmly establish the concept of a belief in one God. Also, the first to link morality with God and made his laws unchangeable. However, many other religions flirted with this concept as well before them. The most notable was the Egyptian Pharoah Akhenaten who abandoned polytheism during his reign in favor of worshipping one god, named Aten. However, after his reign, his predecessor returned to polytheism.

His change to monotheism was not widely accepted. As a result, after his death, they tried to wipe him out of the history books by dismantling his statues, destroying his monuments and keeping his name excluded from the king's list.

It is like going from swinging to monogamy. All those interesting Greek and Roman gods turn into an impotent or pedofile bastard. Deplorable!

Isaiah 19:25 The LORD Almighty will bless them, saying, "Blessed be Egypt my people, Assyria my handiwork, and Israel my inheritance."

Deuteronomy 6:4 Hear, O Israel: The LORD our God, the LORD is one.

The God thingie out of Egypt mythology inherited israel and was just one God thingie then left Israel and conquered all the Roman gods and set up christianity with just one God thingie.

Religions based on many gods - polytheistic, can accept more gods into their reality. Therefore they accepted and tolerated monotheistic religions ( Christianity and Islam). Monotheistic religions actively eliminate their opponents. Polytheistic religions simply lost the battle and perished. All religions so far , that opposed Christianity or Islam have perished so far.

Persistence