Israel Folau has linked Australia's bushfire and drought crises to the nation's legalisation of same-sex marriage and abortion.

In a 10-minute-plus sermon at his church in Sydney on Sunday, the sacked Wallabies player questioned whether it is a coincidence that Australia has been hit by destructive climate-related issues soon after the 'yes' vote.

"The message that I want to speak about today is mainly for the people that are outside (the church) within the world," he began.

"I've been looking around at the events that's been happening in Australia this past couple of weeks with all the natural disasters, the bushfires, the droughts and all these things that are currently happening.

"I'm doing this out of love for people to be able to hear this message and receive it with open hearts."

Folau, whose sporting career is in limbo amid a court challenge, claimed Australians could solve the problems by repealing the laws.

"I am speaking to Australia - they have changed this law and changed the ordinance," he said.

"They have changed that law and legalised same-sex marriage and now those things are okay in society, going against the laws of what God says.

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“Abortion - it's okay now to murder and kill infants, unborn children, and they deem that to be okay.

"This scripture is speaking to Australia. You have changed the law and changed the ordinance. Look how rapid these bushfires, these droughts, all these things that came in a short period time.

"You think it's a coincidence or not? God is speaking to you guys, Australia, you need to repent and you need to take these laws and turn it back to following what is right by God, what God says in his word."

Four people have died in NSW alone as bushfires continue to threaten homes in the north of the state and Queensland.

'Watch and act' alerts are still being employed, nearly a week after NSW declared a state of emergency.

Firefighters watch on as the Gospers Mountain fire approaches a property at Colo Heights, north west of Sydney, on November 15. Credit: DAN HIMBRECHTS / AAPIMAGE

Folau, a devout Christian, suggested the worst is yet to come, making reference to Sodom and Gomorrah.

"What you see out there in the world, it's only a little taste of what God's judgment is like," he said.

"The news now are saying that these bushfires are the worst they've ever seen in Australia - they haven’t even seen anything."

Chevron Right Icon 'Australia, you need to repent and you need to take these laws and turn it back to following what is right by God'

Folau remains locked in a legal battle with his former employers Rugby Australia, who tore up his multimillion-dollar contract this year.

The 30-year-old is suing RA and the NSW Waratahs for $10 million in damages.

But he holds no regrets over posting the messages that sparked his downfall just months before the Rugby World Cup.

Israel Folau departs his conciliation meeting with Rugby Australia at Fair Work Commission in June. Credit: Mark Metcalfe / Getty Images

The post - saying drunks, homosexuals, adulterers, liars, fornicators, thieves, atheists and idolators would go to hell unless they repented - remains on his Instagram profile.

"I knew it was going to be offensive to a lot of people," Folau said at the Australian Christian Lobby's national conference in October.

He also reportedly said he "absolutely" would make the post again.

- with AAP