The Star Wars films introduced viewers to the idea of "the Force" and to "Jedis". It's hard to explain either briefly but Jedi knights protect peace in the universe and harness the power of "the Force" to assist them.
In 2001, an online campaign was started by a Star Wars fan (superfan?) suggesting that "Jedi" should be recognised as an official religion because so many fans of the film franchise actually believe in (or at least claim to believe in) the Force. As a result, in the national census in the UK that year, many people (myself included) registered their religion on the official form as "Jedi".
You can read more about the campaign
here.
However, post #1 is not factually correct (and still not grammatically correct) because Jedi still hasn't been recognised officially as a religion.