Religion:
Belief in and reverence for a supernatural power or powers regarded as creator and governor of the universe.
A personal or institutionalized system grounded in such belief and worship.
The life or condition of a person in a religious order.
A set of beliefs, values, and practices based on the teachings of a spiritual leader.
A cause, principle, or activity pursued with zeal or conscientious devotion
Although I do agree with your definition of religion I (being an Atheist) must disagree with Atheism being a belief. Because what could it possibly be considered a belife in? So I put forth that Atheism is not a belief bu an idea.