The new age of activist atheism, which began with the publication of bestsellers such as Richard Dawkins's The God Delusion (2006), and Christopher Hitchens's polemic God is Not Great (2007), has grown into a loose global coalition of civil libertarians, liberals and gay rights activists. Australians, notorious for their political complacency, have begun to join up. Membership of the Atheist Foundation has increased since 2001, Nicholls says, although he refuses to release numbers. Next month the incipient Australian movement will come together for the Global Atheist Convention in Melbourne. Speakers include Dawkins, the movement's supreme deity; the philosopher Peter Singer; and Dan Barker, a prominent American atheist activist and former Christian preacher. Organisers say it is the largest such event to be held in Australia, and perhaps in the world. The 2500-capacity convention is sold out and there is even a waiting list. ''It started with the scandals of the televangelists in America, the [paedophilia] scandals of the Catholic Church, and then there were the attacks on the Twin Towers,'' Nicholls says of atheism's recent popularity.

''People began writing books that gelled with the population. People realised if they wanted change in society, they had to make it happen. Religion was getting a free ride.'' Tanya Smith, a 35-year-old financial services professional and one of the volunteer organisers of the convention, says the religious lobby is a well-funded, well-organised force that has a disproportionate influence on politics. Atheists would like to ''neutralise'' that influence. ''I want laws that will make society better, not laws based on a book that was written two thousand years ago,'' she says. This is the chief cry of the Australian atheist movement - that religion plays too great a role in politics. They point to Kevin Rudd's on-camera churchgoing, Tony Abbott's controversial views on abortion, the refusal of both leaders to support gay marriage, and the fact that the balance of power is in part held by Steve Fielding of the conservative Christian party Family First.

''A lot of people who don't believe have got fed up with the political role of religion,'' says Russell Blackford, an author and philosopher who will address the convention. ''They see the enormous influence of religious groups, they see Christian lobbies opposing abortion and gay rights, and there is a feeling that, 'They've got their say, it's about time we had a say as well.' '' Atheists such as Blackford have no problem with the Christianity of Rudd or Abbott but they object when it informs policy-making. ''What worries me is when their Christian morality fails to give gays rights or claws back abortion rights, or unfairly advantages churches in terms of tax breaks,'' he says. Dr David Hohne is a theologian and philosopher at Moore College. He names state-subsidised religious education, charity and healthcare as tinder-box issues between the faithful and the faithless.

If a religion accepts state-funding and tax breaks, should it be able to absent itself from, say, anti-discrimination labour laws? ''You get a clash of cultures,'' Hohne says. ''Should Christians be forced to hire a Muslim, a homosexual or an atheist?'' He is quick to condemn any homophobic or aggressive policies that result in discrimination. He admits that where faith-based communities are receiving state money, ''they have to weigh up very carefully the extent to which they want to keep themselves separate from state laws''. The debate becomes more complex when the state seeks to regulate the religious sphere. Atheists are traditionally aligned with libertarianism and civil rights, but religious organisations increasingly complain that a militantly secular state represses the rights of the faithful. Recent examples are the touted burqa ban in France and proposed legislation in Britain that would require religious organisations to justify hiring discrimination against gays for church jobs. Pope Benedict said recently that the legislation violated ''long-standing British traditions'' of freedom of speech and urged Catholic bishops to protest against it.

Hohne says atheists must realise a secular state does not mean a state devoid of religion - that in itself is a form of extremism. As atheists organise and unite, they increasingly face the criticisms they are used to levelling against their faithful counterparts - that they are extremists, skewed fundamentalists. Others warn that strict adherence to evolutionary theory leads logically to social Darwinism. Hitchens is often accused of recycling arguments and of demolishing his marks with one-eyed fervour. His targets include Mother Teresa, a woman well on her way to canonisation. Dawkins has been criticised for his ignorance of Christian theology, and his inability (and that of science in general) to disprove the existence of God. Hohne sees the new atheism as ''a hangover from the 19th century'', when people began to mistrust the idea of knowledge bequeathed by a deity and instead put faith in the power of individual inquiry, through science and rational argument.

Dawkins and Hitchens are on a ''crusade'', he says, but Blackford rejects any such label for his tribe. ''Some atheists are accused of being fundamentalists but that is unfair,'' he says. ''You won't find many high-profile atheists who are extreme politically, in that they want to use the power of the state to suppress religion.'' If such atheists exists, they are likely to make their voices heard at next month's convention, to be held at the same venue as the recent Parliament of World Religions. As Hohne says, in this debate it is near impossible to sit on the fence. Loading

''It's awfully sharp up there.'' Jacqueline Maley is the Herald's religion reporter.