Or think about all the stars in the cosmos.
And, although there are trillions of cells in the human body, there are only a few different types of cell. Think of how every cell in your body is designed to play a specific role or function. We are all parts of a greater whole-the evolving consciousness of all-that-is. The word “role” refers to the fact that we each serve a particular type of function in the great scheme of things. Similarly, when the Source of all being (God, the Tao, the Absolute, whatever you like to call it) casts its consciousness into the relative world, it comes out in the form of individual souls of seven types: What are the roles?
When we cast light through a prism, it comes out in the form of a spectrum which we perceive as the seven colours of the rainbow.