Is there a legitimate basis for religious exemptions from laws that prohibit gender identity discrimination on the basis of people’s beliefs? The author argues that much depends upon how gender dysphoria is understood. If it is seen as a problem requiring medical diagnosis and treatment, then arguably there is no religious basis for discrimination, except in a few situations where being a biological male or female is theologically essential to a particular role. Transgender identification, understood as a medical issue, fits within a belief system that God created two sexes of human beings, male and female. Within that belief system one can make room for an understanding that there are those who experience disorders of sex development and those who have such a profound sense of being born in the wrong body that they undertake steps toward medical transition to align their bodies, as far as possible, with the opposite sex. However, recent reinterpretations of what it means to be transgender involve an assertion that it should not be seen as a medical issue, that affirmation of a person’s self-declared gender identity, with or without having hormonal treatment or surgery, is a matter of human rights and that the law should recognize that people may have a gender that, however described, is nonbinary. These views rely on certain beliefs and positions that have a very weak basis in science. They challenge religious beliefs, which accord with mainstream scientific understanding, that human beings are intrinsically a sexually dimorphic species. People of faith need the freedom to reject beliefs that are incompatible with their worldviews. That does not mean that ill-treatment of someone on the basis of their gender identity can ever be justified; but it does support a religious exemption from a legal obligation to accept someone else’s self-declared gender identity. It is one thing to ask me to respect your beliefs about yourself. It is another to ask me to act toward you as if I share your beliefs.