We should accept everyone's declared sex and gender for two reasons. The ideal idea that anyone's biology is defined at conception is deeply flawed and in Canada's legal system the recognition of the sex or gender of others as different than at conception causes no negative consequence on anyone.
All that TERF rhetoric makes you think about how almost all crimes are committed by cisgender people. [a mediocre parody of hatred]
Inclusion is for everyone - except those who oppress others. If faith needs its own pride flag, let's ask for design ideas from people of faith that have not oppressed others.