How can people with profoundly different basic beliefs about the nature of the universe, God, humanity, right and wrong, and the afterlife live with each other, side by side? At most stages of our history thus far, the answer has been that we can’t.

Burmese Buddhists attack their Muslim minorities. Hindus target Christians in modern India (and vice versa). Christians hunted down Muslims across Europe and the Middle East during the medieval Crusades. And last month, the extremist Islamic group known as ISIS beheaded Coptic Christians in Libya because they came from “the Nation of the Cross”.

The 20th century tried to answer the problem of how we religious human beings might live together by eliminating God from the discussion. Let’s pretend we aren’t religious, and see how that goes. But it too conducted the experiment with violence, led by Pol Pot in Cambodia, Mao Zedong in China, and Joseph Stalin in Russia.

For many, the 21st century answer hasn’t changed: they want God out, or at least out of sight. But such thinking is, well, so last century. A vibrant, less bloody 21st century requires something different, something other than the failed experiments of secularism that we have seen across the past 150 years.

These days, we are living closer to the “Other” than ever before. Cheap transport, global media and shifting labour markets have meant that your neighbour is likely to believe something quite different to you. Vastly different worldviews live side by side, awkwardly, tentatively, often not voicing those differences lest someone capsize the precariously balanced boat that is today’s Australia

But this won’t do. Religion must have a voice, and a place to stand, in a truly civil society. Religion must also have ears to listen to the rest of society. Silence and deafness are not viable options.

So, how can we get there in today’s Australia? There are roughly four options.

First, we could aim for a barely religious society. In this option, religion is barely present, only raising its head in matters related to how it conducts itself in private: rules around its gatherings, communications, rituals and behaviours. This way, no one outside of Islam has to think much about what Islam brings to Australian life; no one outside of Christianity has to think about Christianity. Frankly, this doesn’t do justice to the pervasive impact that religion has on the lives of individuals, families and communities. It can’t be kept behind closed doors. And we all know now, thanks to tragic events, that it won’t stay hidden anyway.

Second, we could aim for a commonly sacred society, where one set of religious laws and customs becomes the “Australian Way”. This might be a blend of religious views, perhaps according to the proportion of Aussies who hold them; it would be a synthesis of religions based on majority principles. In the past, a version of this occurred, where Christian thinking was a default for Australian culture. But those days have gone, and we are in a vastly different environment when it comes to public attitudes to family life, sexuality, religious expression and social standards.

If it were possible in the past to “live out Christ’s lordship” in the form of legislation and culture, it is not today. Christians would do well to realise this and think afresh about how to express their faith in a much more complex and varied Australian culture. At the same time, this kind of civic religion doesn’t really keep religious adherents of any kind happy; it only works for the “all religions are really the same” types.

A third option is to have a secretly religious society, where people act according to their religious convictions but without naming them. People keep their ultimate motivations to themselves and get on with things. This is close to how leaders behave today, where expressions of faith commitments are ruled inappropriate most of the time. If one’s views on, say, gay marriage are informed or grounded in a religious commitment, that is unlikely to form part of the public conversation of the issue; other, more commonly accepted authorities – such as science, medicine, sociology or opinion polls – are considered more acceptable than religious reasons. But this just leaves people to be duplicitous and dishonest. It can’t be the way forward.

My preferred option for religious pluralism in Australia is a noisily religious society. I don’t just mean Hillsong on a Sunday morning, I mean a public square where we expect to hear the robust, outspoken, argumentative and complicated voices of religious people, whether in agreement or disagreement. Where people don’t get pigeon-holed or blacklisted for talking about their theology, and where it is just openly accepted that human beings are often motivated by profound religious commitments, which can differ radically from one’s neighbour’s.

This noise will be hard to take, rough on the ears and tough on the emotions. It will leave people angry, baffled, shaking their heads at what others believe. But it is a better way. The babble of the Areopagus (Acts 17) led to sneering and confusion, but it also gave the apostle Paul a bloodless hearing. That’s a good outcome.