I made my joke answer, now I will make my real one. Religion, no matter how good it's original intention, is always a tool to control the minds of people.
Anything that requires you to have blind faith and follow some rules, cannot work out well for its followers. Why? Because no set of rules however good can give unequivocal guidance in every situation; so the religion has to appoint people to interpret the rules and tell others what to do. Now you have leaders who can't be challenged by the followers, and maybe that's OK, but there is a lot of evidence that this power is often abused. This isn't just pure spiritual religion either, but any belief system like extreme fascism or communism too.
So there is no religion I could make that I would ever feel is fit for purpose.