Today is Star Wars Day, being May the Fourth. (Say the date slowly, several times.) Around the world, film buffs, storm troopers and Jedi are gathering to celebrate one of the greatest science fiction romps of all time. It would be easy to let the fan boys enjoy their day and be done with it. However, Jediism is a growing religion in the UK. Although the results of the 2001 census, in which 390,000 recipients stated their religion as Jedi, have been widely interpreted as a pop at the government, the UK does actually have serious Jedi.

For those of you who, like BBC producer Bill Dare, have never seen Star Wars, the Jedi are "good" characters from the films. They draw from a mystical entity binding the universe, called "the Force". Sporting hoodies, the Jedi are generally altruistic, swift-footed and handy with a lightsaber. Their enemies, Emperor Palpatine, Darth Vader and other cohorts use the dark side of the Force. By tapping into its powers, the dark side command armies of demented droids, kill Jedi and are capable of wiping out entire planets.

Jediism is a growing force. Photograph: Church of Jediism

This week, Chi-Pa Amshe from the Church of Jediism in Anglesey, Wales, emailed me with some responses to questions. He said Jediism was growing and that they were gaining hundreds of members each month. The church made the news three years ago, after its founder, Daniel Jones, had a widely reported run-in with Tesco.

Chi-Pa Amshe, speaking as a spokesperson for the Jedi council (Falkna Kar, Anzai Kooji Cutpa and Daqian Xiong), believes that Jediism can merge with other belief systems, rather like a bolt-on accessory.

"Many of our members are in fact both Christian and Jedi," he says. "We can no more understand the Force and our place within it than a gear in a clock could comprehend its function in moving the hands across the face. I'd like to point out that each of our members interprets their beliefs through the prism of their own lives and although we offer guidance and support, ultimately like with the Qur'an, it is up to them to find what they need and choose their own path."

Meeting up as a church is hard, the council explained, and members rely heavily on Skype and Facebook. They have an annual physical meeting, "where the church council is available for face-to-face questions and guidance". They also support charity events and attend computer gaming conventions.

Meanwhile, in New Zealand, a web-based group called the Jedi Church believes that Jediism has always been around.

It states: "The Jedi religion is just like the sun, it existed before a popular movie gave it a name, and now that it has a name, people all over the world can share their experiences of the Jedi religion, here in the Jedi church."

There are many other Jedi groups on the web, although Chi-Pa Amshe said some were "very unpleasant". The dark side, perhaps.

Analysis of all six films reveals echoes of many religions in the Force. Star Wars is, in essence, a type of multi-faith casserole. Christianity features heavily, for example. This is manifested in the puzzle of Anakin Skywalker's conception, by phrases such as "May the Force be with you" and an overarching redemption theme. Yoda critiques Luke for his lack of faith. "Try not. Do. Or do not. There is no try."

Judaism is prevalent in the constant tensions between good and evil, loyalty and fatherhood. The religious ideology of Buddhism is there, focusing on the art of meditation and reducing the passions that taint the soul. Meanwhile the Hindu concept of Om, representing a power present in all things, is never far away. In The Empire Strikes Back, Master Yoda explains the Force. "My ally is the Force. And a powerful ally it is. Life creates it, makes it grow. Its energy surrounds us and binds us. Luminous beings are we, not this crude matter."

George Lucas claims that Joseph Campbell's book The Hero With a Thousand Faces was a major influence behind the Force's creation. In it Campbell draws parallels between the world's myths, arguing that they are all part of one "monomyth". In an interview with Bill Moyers, in 1999, published in Time magazine, Lucas said he created the Force as a device to awaken spirituality in young people. "Not having enough interest in the mysteries of life to ask the question, 'Is there a God or is there not a God?' – that is for me the worst thing that can happen." However, he said he never intended Star Wars to have a religious following. "I hope that doesn't end up being the course this whole thing takes," he told Moyers, adding that he would hate living in a secular world where entertainment passed for people's religious experience.

I warmed to Chi-Pa Amshe of the Church of Jediism. I liked the way he signed his emails with MTFBWY – "May the Force be with you". I was surprisingly comforted by it. However, I remain sceptical. Jediism belongs in the star systems of Lucas's mind. For me, having one gigantic monomyth in place of distinct religious or secular systems sounds like chaos. In the 70s and 80s, when the first three "real" Star Wars films were made, the Force was tapping into the zeitgeist, basking in a postmodern world where all religions led to God. Perhaps another reason the later three films were never as popular is that fewer people buy into that worldview anymore.

• This article was amended on 4 May 2012. It originally quoted Chi-Pa Amshe as saying that members of the Church of Jediism interpret their beliefs through the prison of their own lives. This should have read "prism of their own lives". It also referred to Anakin Skywalker's immaculate conception. Immaculate conception does not refer to conceiving without sexual intercourse: rather, it is the Catholic doctrine that Mary herself was conceived by her mother without the stain of original sin