Freedom of religion has wrongly and unfairly been used to deny marriage rights to gay and lesbian Australians and must be strongly resisted, Labor frontbencher Penny Wong has said.

In a rallying call for the separation of church and state, the South Australian senator blasted religious fundamentalists for limiting the freedom of "those who do not 'conform' to their views".

"Religious freedom means being free to worship and to follow your faith without suffering persecution or discrimination for your beliefs. It does not mean imposing your beliefs on everyone else," Senator Wong told the NSW Labor Lawyers gathering on Tuesday night.

"And it most emphatically does not mean deploying the power of the state to enforce one set of religious beliefs. One's own views should not determine the rights of others."