Given this definitions:
Faith: Believing in something without proof.
Cult: A group of people sharing a common faith.
Religion : A cult with many followers.
If someone teach you X. Without offering proof you understood. And instead of trying to understand the proof to find if it makes sense or is Bullshit, you automatically accept it. Then you are having faith.
If another person does the same and you are two, then you have a cult, as none of you use proof to accept what was taught. You just accept it out of faith. Or you pretend to accept it out of hypocrisy and peer pressure.
If many people do exactly the same. And accept things, not because they understood the proof, but because they accept it by faith. You got a religion.
My point is that churches are not the only religious group.
- You got patriots who believe they live in the greatest nation on earth. And you got it in every nation.
- You got people that believe that somehow the state owns the individual and thus the individual should always obey.
- You got people that believe in global warming (sorry human made climate change).
- You got people who believe that tabs should be banned, while others consider this heresy.
- You got the vim religion, you got the Emacs religion.
- You got the big bang (where did the energy came from?)
Anything that is not based on direct observation and understanding of proof. Is faith. And thus you got millions of religion. Not all of them teist. (Except maybe for statist, who believe that the state is god :))
Even atheism is a religion. Do you got proof that there is no such thing as a god? If not, your belief is based on faith. So, congratulations, you are part of a religion. As there is no way to proof the existence or non existence of a deity (as a deity can hide its existence and a non deity with enough technology can simulate being one to those with less technology). The only non religious believe is "I don't know."
Unless of course you are God, then you are either crazy, or telling the true.