Ranging from sectarianism to sex, a four-day event nicknamed the "Muslim Glastonbury" is setting out to challenge perceptions of Islam in Britain.

Living Islam, which began on Thursday at Lincolnshire Showground and continues over the weekend, is a celebration of Eid al-Fitr, which was marked by Muslims around the world this week at the end of the holy month of Ramadan. But the festival, perhaps more akin to a Muslim Hay-on-Wye than the music festival it has been compared to, also represents an opportunity for the expected 4,500 attendees to discuss the issues pertinent to them in contemporary Britain.

Dilwar Hussain, one of the organisers of the Islamic Society of Britain event, being run for the fifth time, said the range of topics being covered should not come as a surprise. "British Muslims are a broad range of people, they're not just interested in one thing. They have diverse interests and they shouldn't be stereotyped as extreme or non-extreme, passive or moderate."

The discussion programme ranges from sectarianism in the UK and tackling extremism to Saturday's opportunity to "have a frank and honest conversation about sex and relationships" and Sunday's segment on how to "spice up your marriage". Hussain said the topics reflect "Muslim table talk, what people ordinarily discuss in their homes".

"It's true to some extent that we don't publicly talk about these things and what we are saying is actually, these things should be talked about," he added.

But the festival is not just about earnest discussion. The entertainment tent, a Glastonbury-style big top, featured rapping, beatboxing and comedy on Thursday night and there are a huge range of activities, including supervised scout activities, bouncy castles and rock-climbing to distract the children while parents attend to more serious matters.

Mary MacIntyre, a 42-year-old teaching assistant from London, eating a seekh kebab in the smoky food tent on Friday – food being a key part of any Muslim festival – said her family had come with two other families, with 20 children between them, and were camping on site. "We thought it was a good thing for them [the children] to be in an Islamic environment so they can see their religion as something positive," she said. "You can still enjoy yourself as a Muslim. They can come here and be proud of their identity."

Rowan Williams, the former Archbishop of Canterbury, one of a number of non-Muslim speakers, gave a talk entitled "What do British values look like and is there room for Muslims?" He expressed his unease about focus on British values rather than values of human beings generally. "The setting-up therefore of British values against any kind of values, whether Muslim or Christian, just won't do," he said. He told the Guardian Living Islam was "a very important event. I've thought for a long time that voices of young professional Muslims aren't heard enough."

One of those young professional Muslims was Nadia Ishtiaq, from London, who said Williams's words resonated with her. She and her husband were camping with their two daughters for the first time after chancing upon details of the event online.

Speaking as they all tucked into Halal burgers, the 31-year-old, who works in accounts, said she liked the fact that Christians like Williams were speaking, as well as Muslims from different strands of Islam. "It's really diverse, I love that," she said. "Sometimes Muslims can be quite cliquey. As British Muslims, we do try to get involved with our neighbours. Muslims shouldn't make themselves exclusive, we are an inclusive faith."

Ajmal Masroor, the imam of TV fame, including "Make me a Muslim", said the event was helping to create "positive citizens of this country".

Explaining what people could expect from his seminar on love, sex and relationships on Saturday, he said it would be "everything about sex you want to know from a Muslim perspective. According to Islam, sexual experience is a heavenly glimpse of what's to come. Most of us want it to last forever, but if it did you would be in heaven [already]."