“When they signed Folau again, it didn’t occur to anybody that he would do exactly the same thing,” said Peter FitzSimons, a former national rugby player and now a columnist and author. “You couldn’t believe that somebody would take a contract for 4 million dollars and do exactly the same thing as he had done last year, but he did.”

To some in Australia, where the Christian foundation remains broad despite the increasing secularism, the debate over Mr. Folau’s comments is a fight over religious freedom. Mr. Folau has defended his posts by saying he would not hide his faith to suit his employer, and his lawsuit accuses Rugby Australia of religious discrimination. Some who have contributed money to his cause have pointed to questions of freedom of speech, too.

The case has also highlighted cultural divides between Australian athletes of Pacific Islander descent and their teammates. Nearly half of the players on the national rugby squad have family ties to the Pacific islands, and they largely share the evangelical religious beliefs of Mr. Folau, who was born in Australia and is of Tongan heritage.

“Might as well sack me and all the other Pacific Island rugby players around the world because we share the same Christian beliefs,” one player, Taniela Tupou, wrote on his Facebook page last month after Mr. Folau was fired.

If Mr. Folau’s case goes to the High Court, the top court in Australia, it may come down to whether his contract placed an unreasonable burden on his right to practice his religion, said Gillian Triggs, a former president of the Australian Human Rights Commission.

But many Australians see the debate not as a matter of religious freedom but as a reflection of a conservative backlash over a referendum two years ago that paved the way to same-sex marriage.