How did Jewish faith start?

Answer:
Someone claimed to have had a revelation and spoken to a god. This god gave him instructions to worship him and convince others to do the same.

Much the same as many other religions.

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Or, much like many other religions, it may have stemmed from a series of teachings and guidance or questions and answers that people had about the world around them, as well as how to interact with one another and how to treat one another and what is "proper", etc.
First answer by Lazarus. Last edit by Robsidious. Contributor trust: 32 [recommend contributor recommended]. Question popularity: 2 [recommend question].