Monotheism and its development in Israelite religion is a topic that continues to invite scholarly engagement. Some of the key talking points around it involve whether or not it was developed before or after the exilic period. At the same time, and irrespective of when it was introduced into Israelite religion, the circumstances that facilitated its development have never been acknowledged with unanimity. The purpose of the present study is two-fold: first, it seeks to prove that pre-exilic Israelite religion was as syncretistic as any other ancient Near Eastern tradition, and that exclusive monotheism only became a reality in Persian period Yehud. Secondly, the study is also intended to authenticate the hypothesis that in the wake of the development of monotheism in Yehud, all deities other than Yahweh were demoted to the status of מלאכים, messengers (angels) leaving Yahweh as the only legitimate God.