I think you need to be born Jewish for it to be fashionable though.
First thing you need to start a new religion is a prophet. This prophet must have something to offer that a group of people need. And he must not be so crazy as to be dysfunctional but not so sane as to be unable to hear the voice of God.
Imagine starting a new religon.... how exactly would you figure out what divine entity holds dominion over your Earthly body, just what are it's rules and expectations, how does it feel about you, and what kind of rewards would it hand out? If your plan is to talk about specifics, what specifically would you talk about?
Of course it would help immensely if one day you stumble across this book that some people wrote up as stories several thousand years ago and that a group of religious devotees got hold of, restructured, rewrote it and then published it as the "word of God" The long lost rules of God! Again, who put this stuff into writing and what gives it the authority of truth? What differentiates it from a comic books?
My illustration demonstrates that making up stuff is hard. Latching onto some ancient story is convenient, but does it inherently contain truth or just a bunch of ancient superstitious mumbo-jumbo? The answer is unknown. Just because it makes you "feel good" does not qualify as truth. You may be gladly kidding yourself.