Australians may not go to church as often as we used to, but there’s no escaping the influence religion has over our lives.

Socially and politically, religious leaders are using their clout and followers to influence the national debate on topics such as gay marriage, euthanasia and abortion. It’s not just the cardinals, rabbis and clerics who are shouting from the pulpit either. Religious lobby groups are making noise — and getting results.

Then there’s our reliance on religious-backed social services, such as hospitals, schools and aged care facilities. From the cradle to the grave, the government is increasingly looking to the church to take care of us.

Who’s putting religion into our lives? It’s a sermon ripe for scrutiny …

Tim Costello (CEO World Vision)

The brother of a federal treasurer and perhaps the most recognisable Baptist minister in the country, Costello is a go-to voice for the media on social justice issues like gambling, poverty and homelessness. World Vision, a Christian evangelical group, is Australia’s largest charity, with $345 million in revenue in 2011 (including $41.2 million in AusAID grants).

Samier Dandan (president, Lebanese Muslim Association)

Based out of Sydney’s Lakemba mosque (one of the biggest in the country), Dandan is the slick political operator at the head of the Lebanese Muslim Association. The LMA’s full force was felt at last year’s NSW state election, where Dandan threw support behind a swag of Liberal candidates in seats with high Muslim populations.

Bill Daniels (executive director, Independent Schools Council of Australia)

Mention the words “private school funding” and not far away you’ll find Bill Daniels, adversary of those who want more money for public schools. He’s not really a religious leader himself, but he does represent Christian, Islamic and Jewish schools (and other non-religious independent schools).

Vicki Dunstan (president, Scientology Australia)

Scientology may be a mere blip on the spiritual radar — there are 2163 Australian devotees according to the 2011 census — but the controversial organisation still gets tax exempt status. That’s despite a political push from people like Senator Nick Xenophon to repeal it. Even celebrity followers like James Packer and Lachlan Murdoch have backed away from what many call a dangerous cult.

Brian and Bobbie Houston (founders, Hillsong Church)

The rockstars of the evangelical scene, the Houstons began their Pentecostal megachurch in Sydney’s Hills district in the ’80s. It’s gone on to become a worldwide phenomenon, with churches in London, New York City and Moscow. Backed by a slick marketing effort and a music label powerhouse that has sold more than 12 million records, Hillsong just keeps getting bigger.

Peter James (CEO, Scripture Union Queensland)

The National School Chaplaincy Program hit controversy this year, after Queensland father-of-four Ron Williams successfully brought a High Court challenge against the $222 million plan. Nevertheless, federal funding for chaplains in schools continues unabated (after being increased under the Gillard government), with the Scripture Union providing the lion’s share.

Peter Jensen (Anglican archbishop, Sydney)

One of loudest voices in opposition of gay marriage, Jensen made headlines recently for telling parishioners that changes to the Marriage Act could lead to polygamy and incest. He has also attacked atheism, calling it a form of self-idolatry, and linked secularism to loneliness. As one of the most senior Anglicans in the country (out of 3.7 million), he has sway.

Martin Laverty (CEO, Catholic Health Australia)

It’s easy to forget how much of our health and aged care is provided by faith-backed organisations. One of the biggest is Catholic Health Australia, with 19,000 aged care beds and 75 hospitals (24 of which are public). With size comes the power to refuse certain services, such as abortion and birth control. Laverty says Catholic hospitals are up front about procedures they can and can’t do.

*Read the full list at The Power Index