When he is born again. Followers of Christ were first called Christians at Antioch.
Those who claim to be Christians, or rather Christian, who don’t put their trust in Jesus are only acting out Christian behavior, which is not what makes one a Christian.
Our culture has perverted the meaning of the label of Christian.
Kindly permit me a slight correction to your observation: Liberals are trying to inflict their culture, which includes a monstrous perversion of Christianity, on Western Civilization Culture. And I must say they have been largely successful at the enterprise.