‘Judeo-Christian/Islamic’ monotheism was first practiced by Cushites. The concept of a single god associated with the sky and evil represented by spirits.Allah and El both mean "The God" in Arabic and Hebrew, respectively. They still had a pantheon of minor gods and goddesses.
Zoroastrians were the first monotheistic religion group and worshipped Ahura Mazda as their chief god, but even they worshipped minor gods and spirits.
These ideas were from the Nile valley but Cushites were first to adopt it according to Ehret.