Let’s start by asking: what IS a religion? Very broadly, a religion is a collective way of thinking about spiritual matters. It’s a group-think choice to believe — or to NOT believe — in a wide range of spiritual questions, including god(s), other god-like beings, the afterlife, and our place in the universe. Most religions also include a lot of other stuff, too, such as lessons on ethics and morality, fashion guidelines, and celebratory rituals to mark important weekly, annual, and life-milestone events.
The spiritual beliefs which our members share are that all gods are imaginary and that death is the end. We also believe in being good people, and in loving and helping each other as much as we can in our limited time on a tiny planet in a vast, uncaring universe. In order to become a Caveman, you must share our beliefs... just like any other religion.
Some might claim our religion isn’t real because it’s all made up. Well, so is every other religion. Ours just happens to have been made up a lot more recently than most. But also, our religion isn’t actually new — it’s a re-discovery. We regard our traditions as being older than anyone’s!