As God was teaching his newly adopted children to prosper the first thing he taught them is that He is one God. What is the big deal? It was a big deal because all the peoples in this time believed in many gods. They looked at the sun and thought their must be a sun god, they saw the rain and thought there must be a rain god, etc. Basically everything they could not understand or influence they believed was controlled by invisible spirit beings.
If there are many gods controlling the universe, then the world is unpredictable. The ancient Greeks believed thunder was the gods getting angry and arguing with each other. It really was a part of the ancient pagan worldview. So if there are many gods randomly controlling things then people will spend their lives endlessly trying to please these gods and always be a victim of them.
But if the world is set in order by one God, that is a different story. That one God has laws that govern the world. Can you say “gravity”? Mankind can learn these laws and actually manage the world in a way that allows them to prosper. God revealed himself to Abraham as the only God who had a consistent and unchanging nature.
Harold Eberle says, “We cannot overestimate the significance of this revelation. It was more profound for the advancement of civilization than the discovery of fire or the invention of the wheel.” The revelation that there was only one God allowed the children of Israel to begin to understand and manage this world.
It is true. It allowed them to prosper. It’s a big deal.