The stack of small yellow cards in the centre of the table do not appear to hold much promise. But to the teenagers at Crown Hills community college in Leicester, they are nothing short of a revelation.

The school has 1,200 pupils – 94% of whom are Muslim. It accommodates pupils who fast, pupils who pray and pupils who cover themselves – so encouraging them to consider and debate atheist and humanist beliefs might seem impossible.

They are among the first students in the UK to study humanism as part of a religious education GCSE and, despite the overwhelmingly Islamic identity of the student body, they enjoy grappling with the concept of non-belief. Each yellow card bears a phrase such as "the universe is an accident, not a plan" and "science has disproved God". The sentences are intended to provoke discussion and reflection.

Without pausing for breath, Kulsum Ali, 13, explains what impact such discussions have on her. "If you have a watch, you see it, someone made it, it didn't just get there by itself. You can say the same thing about the world. It didn't just happen. But if God made the planet, then who made God? It's like a tree, isn't it? It just goes on and on. It makes my head hurt."

Tolerant and transparent

While the price to pay for existential debate is a migraine, the efforts of Crown Hills to introduce atheism and humanism into the classroom has nonetheless earned it a place on an awards shortlist. The inaugural Accord prize celebrates diversity of not only religious but also non-religious beliefs. The award, launched last November by a coalition of religious groups, humanists, trade unions and human rights campaigners, is open to all state-funded schools and is judged by a panel led by Rabbi Dr Jonathan Romain. He says Accord is seeking out and rewarding schools that are "inclusive, tolerant and transparent".

"Not all of Britain is 'broken' – there are also many examples of remarkable success and cohesion – so it's time to praise those schools."

Accord's stated aim is to reform laws governing faith schools, and promote inclusive schools. In the state sector, it aims "to resist the expansion of state-funded religious schools which operate restrictive and discriminatory admissions and employment practices."

For the pupils at Crown Hills, the conversations present a rare opportunity to break taboos. Kulsum and the others agree they would never be able to talk about the big bang and the existence of God at home, at least not where their own religion is concerned. Zunaid Patel, 15, says: "As a Muslim, you believe in Allah. You don't question it. It's a command, you're just told to believe it."

He and his family are Muslim. "My parents understand that you need to know where other people are coming from. You can't judge people because they don't believe the things you do. You can be good without God. You can't think you're better than someone because you have religion and they don't."

The debates are equally stimulating and rewarding for the teachers, who work in a city projected to have a non-white majority by 2020. The staff is diverse too – atheist, Christian, Sikh, Muslim.

Most teachers say they are open about discussing religion and non-belief with pupils. Liz Hewitt, who teaches religious studies, says open discussions make children more aware of society. "They will meet a much broader range of people when they leave Crown Hills. These kind of debates mean they can talk about faith in a more informed way."

Bernadette Green, headteacher, says: "We're not in any way challenging their beliefs. We're very sensitive to them. Our students like RE and it's very popular at GCSE.

Teachers take a thematic approach to teaching religious education. Pilgrimage is important in the many world faiths and similarities are stressed at every opportunity. But there is also a focus on rites of passage such as birth, marriage and death that span all faiths and none.

A similar approach can be found in Barnet, north London, where children of all faiths and none are encouraged to adopt a broad-brush approach to the important things in life – symbols, celebrations and inspirational figures. Manorside primary, which is also on the Accord shortlist, starts from the personal before broadening it out to the religious.

Inclusive

Dianne Cohen, who provides religious education support, says not all Manorside pupils come from a faith background and religious education has to recognise that. "It makes it more inclusive. We always start with the children's own experience so nobody feels left out." One worksheet asks about the children's morning rituals. Answers include brushing teeth, eating breakfast, getting dressed. Some children have written "praying", others have not.

Kwame, who is nine and a Christian, says it is good to learn about other religions. "If every­one was the same the world would be a boring place. People can share what they do during festivals." His friend Frankie, who is also nine, says he has "no religion". "I don't feel left out," he says.

And what do the churches think about the award?

The Church of England says it is "fairly relaxed" about different belief systems – including non-religious – being taught, but that it would "expect" Christianity to be the principal religion taught unless it was a faith school [of another religion].

The Catholic Education Service describes religious education as being "vital, with much knowledge and intrinsic value to offer people". Oona Stannard, its director, adds: "They learn not only about religion and belief and to probe the bigger questions of life, but also about the importance of faith in the lives of others."

The Accord award-winners will be announced at the end of this month. accordcoalition.org.uk

• This article was amended on February 9 and 10 to expand a description of the aims of the Accord coalition.