(CNN) Australia is the closest it has ever been to legalizing same-sex marriage.

On November 15, the Australian Bureau of Statistics revealed 61.6% of Australians had voted in favor of legalizing marriage equality as part of a national postal survey.

In total, 79.5% of Australian voters took part in the voluntary vote.

Australia's parliament will now debate how to turn the people's choice into law, but it could be more complicated than it sounds.

Conservative politician and "no" advocates are calling for extensive religious protections in any bill legalizing same-sex marriage.

It's been a long process -- a national vote was first proposed by the government in 2015, when Australia was already far behind many other English-speaking nations when it comes to same-sex unions.

So why is the issue so divisive in Australia?

What do Australians think about gay marriage?

Almost every poll in the past decade has shown a majority of Australians support same-sex marriage.

As early as 2007, polling showed a majority of Australians were in favor of allowing marriage for same-sex couples. Since then, poll after poll has shown the same thing.

Overall, about four-fifths of Australians are accepting of homosexuality in general, Pew Research data published in 2013 reveals, one of the highest numbers in the world.

Gay rights in Australia haven't always been fast to arrive -- homosexual sex was illegal in parts of Australia up until 1997 -- but on marriage equality their opinion now seems clear.

Why is it taking so long?

In short, politics.

Since then, the campaign to bring same-sex marriage to Australia has slowly ramped up but no government had previously committed to passing it.

In 2013, outspoken conservative and former trainee priest Tony Abbott became prime minister, apparently eliminating all hope of same-sex marriage during his term in office.

To hold the plebiscite, the government needed money and to get that money it need to pass legislation through Australia's parliament.

Two attempts at passing legislation in 2016 and 2017 failed after the opposition Labor party and Greens party helped block it, calling for a simple parliamentary vote legalizing marriage equality instead.

After the last attempt, the government, now under Prime Minister Malcolm Turnbull, said it would instead hold a national postal vote

Speaking prior to Thursday's landmark result, Tiernan Brady, executive director at the Equality Campaign, told CNN that the decision to hold a postal vote was about "the world of politics, not the Australian people."

According to Tiernan, the Australian people had made their minds up on marriage equality a long time ago. "Australia has a higher approval rating for marriage equality than some countries that have marriage equality," said Brady.

Why were same-sex marriage advocates opposed to the vote?

Campaigners feared the survey would provoke a brutal and vicious campaign against same-sex marriage by opponents could be damaging to LGBT people. They said the issue should be decided by parliament, which could in theory to legalize same-sex marriage at any time.

"This is a debate in the public sphere about (LGBT people's) worth in society, their value and that's a hard debate to be a part of," Brady said before the vote.

At the time, Prime Minister Turnbull told LGBT Australians they had to trust their fellow voters.

"Australians are able and have demonstrated that they can have a respectful discussion," he said.

Prior to the vote, a court challenge by gay marriage proponents tried to stop it taking place, saying the postal vote was unnecessary and a waste of public funds.

But a unanimous vote by Australia's High Court on September 7 allowed the vote to go ahead.

Australia is not the first country to have a national vote on same-sex marriage -- Ireland voted to legalize marriage equality in 2015.

"(But Ireland) had to have a referendum because it was a constitutional requirement," Brady said. "We've always said the way this should be done (in Australia) is the way all issues pertaining to people's rights are dealt with, by parliament."

Is gay marriage legal now?

Unlike Australian federal elections, where voting is compulsory, the postal vote was voluntary and also non-binding.

This means the government is not legally obliged to do anything and will have to pass legislation to make same-sex marriage law.

After the vote, Turnbull pledged to have marriage equality legislation passed by the parliament by Christmas, but several conservative politicians have already said they'd vote against same-sex unions despite the result.

The prime minister has repeatedly said his government was obligated to carry out a national vote as that was what he had promised voters at the last election.

"Strong leaders carry out their promises. Weak leaders break them ... You heard me, again, say again and again that every Australian will have a say on this issue," he told journalists in August.

Opposition Labor party leader Bill Shorten also promised after the result to make same-sex marriage law quickly, saying Australia was "overwhelmingly" ready.

"What this marriage equality survey shows is that unconditional love always has the last word," he told supporters in Melbourne.