Roy Williams has, in Post God Nation?, accumulated a substantial body of wide-ranging research to support his deeply felt conviction that Australia, and the world more broadly, has benefited from Christian teachings and action far more than is usually acknowledged. In Williams' view, the benefits radically outstrip past and current human errors. What's more, much of the good we take for granted in Australia is, he argues, a direct result of lived Christian values and endeavour.

His purpose in writing this book – and in undertaking the research to support it – rests with a hope that Australia could become a more meaningfully religious country, by which he means a more meaningfully Christian country. He explicitly respects other faiths. Christianity, though, is the religion he loves and privileges. "Imagine," he writes in his concluding chapter, "if Australia were looked upon by the world not merely as the luckiest country on Earth, but also as the most righteous. A truly Christian beacon of faith, hope and love. …That would be real, deserved 'national security'."

In that same visionary chapter Williams asserts that, "Christian believers are rather more likely than unbelievers to abstain from the worst excesses [of inhumane or unethical] behaviour and indulgences". Many readers, and I am one of them, will read this with considerable sadness. Williams may even share that sadness because he freely takes to task contemporary Christians who fail their espoused values. Among them are some familiar political leaders. But we needn't accept this as inevitable: "Church leaders should take every opportunity to stare down relevant politicians and decision-makers, and ask the toughest moral questions."

A more morally courageous Australia would be immensely desirable. Williams brackets, vigorously and correctly, leadership as well as community attitudes to foreign aid, the treatment of refugees and asylum seekers, and climate change. There he states unequivocally: "Christian attitudes to these issues should be shaped by certain core biblical principles." He includes the famous quote from Luke 12:48: "From those to whom much is given, much will be expected." Indeed.

For that chapter alone, as well as for the array of historical and social analyses that precede it, this book adds substantially to our understanding of religion as a continuing social force that could arguably bring something greater than humanist secular values alone can achieve. Williams usefully includes short portraits of Christians he regards as positive influences in shaping our political and cultural landscapes. With that, he is openly striving to "save" religion as "… an ideological framework that is neither 'right wing' nor 'left wing'", but is also "a potentially precious source of emotional sustenance and ambition; and a form of community attachment that … is unique and valuable".

Much of this is admirable. In fact, for readers who share Williams' views of Christianity as not only the majority faith but also the most ethically developed one, these arguments and the research that supports them will be welcome and persuasive. Few could deny that we would live in a far happier, safer world if Christians lived Christ's sublime teachings, especially when it comes to considering the wellbeing of others above one's own, sharing resources with neighbours (global and otherwise), valuing all lives equally, forgiving wrongdoings and, especially, unconditionally committing to peacemaking and social justice.

Nonetheless, despite the seriousness and honesty of Williams' intentions, I have some reservations. One is personal: that the richly unfolding interiority of a faith commitment rarely appears on these pages. For me, that's what gives life its deepest truth and meaning. I wish it had been more nakedly glimpsed here. More generally, in arguing so strenuously for the good that the Christian institutions and faithful have achieved, I couldn't help but feel that Williams underplays the myriad of ways in which, in the name of Christianity, distinctly un-Christian values have damaged or destroyed lives.

Women, people of every colour other than white, gays, non-Christians: all have been radically harmed by misogyny, racism, homophobia, religious ignorance and prejudice (and forced conversions) endorsed by Christian institutions and the men who run them. Some of this continues. Williams certainly acknowledges this, as well as recent revelations of child and sexual abuse, yet seems not to fully appreciate the soul-wrenching harm done, even between different expressions of Christianity in the name of "authority" and "heresy".

Readers may also question whether he sufficiently values or understands the depth of ethical teachings in other faiths. Within Buddhism, for example, teachings on free will and the power to choose, as well as the value of life, compassion, peacemaking and the unity of all beings have reached a level of sophistication and practice that Christian institutions and leaders could well learn from. Our chances have never been better to benefit from the accumulated wisdom of all faiths, and particularly from what they share. That, too, offers a fine and renewing vision of hope.

Reverend Dr Stephanie Dowrick leads interfaith services at Pitt Street Uniting Church. Her books include Seeking the Sacred.