[GunRunner]

As for belief, it’s broader and deeper than simple preference or inclination. Belief, the way I’m using it here, is world view.

If religion is now synonymous with worldview, then I would say that atheism, non-belief, and agnosticism are a part of one's worldview. I don't see how you can call them religions in the same way as a Christian or a Muslim. It's essentially non-participation. It is not non-belief in everything.

[reasonisfaith]

My Christian faith is non-participation in Buddhism, for example.

It’s also non-participation in the belief that a material existence and accompanying lifestyle is the best choice.