Now. mostly likely you have never heard of “syncretism”. For many people it is a unheard of term because it is usually replaced with the word polytheism. However, syncretism goes much deeper than polytheism.
Polytheism is a religion with many gods, Syncretism is a religion that is a broad mixture of different religions and gods. If you were a farmer and there was a god of the ground, then you might want to add him to your religion and sacrifice to him so that he will bless your crops. I mean, why not? If he is real, then you benefit; if he is not real, then you don’t lose much.
In the ancient world, the culture was literally saturated in syncretism. Despite the common belief, the Israelites were not polytheists when they worshiped other gods. They were syncretists. To them, God was their national God; usually the leader of the other gods. The Israelites still believed in God, but they mixed that truth with a bunch of other lies. That is why you hear God say so many times in the Bible that He is the only God.
Thus saith the LORD the King of Israel, and his redeemer the LORD of hosts; “I am the First, and I am the Last; and beside Me there is no God.”