Monotheism is the belief in one single deity as opposed to multiple deities. Christianity, Judaism and Islam are the most recognized monotheistic religions today. It isn’t as known by people, but other ancient religions were also monotheistic! Zoroastrianism was a monotheistic religion created in Persia. It was lead by their own prophet named Zarathustra and scholars think it was the first to develop angels, a day of judgement and a Satan-figure. It was founded around 1000 BC! There was also a pharaoh in ancient Egypt that made the sun-god the only god and destroyed the other gods. It was called the Aten cult. It is believed that those two religions influenced religion in the middle east. They may have come in contact with the Israelites and shared their beliefs including monotheism. Stories were discovered of the Israelite god, Yahweh interacting with other lesser deities around the 14th century BC. The stories were battles where Yahweh came out the winner! He later developed to be the only deity. Christianity has a more awkward form of monotheism with their trinity of god, his son and the holy ghost. They’re all supposed to be one and three different entities at the same time. Judaism and Islam reject the trinity and it was historically (and today) debated if that counts as polytheism.