Many religious beliefs assert that your birth gender is your God-given identity. We have no right to challenge God's actions or acknowledge any trans citizen's self-defined gender identity.
Any society that promotes a tolerant view of religious freedom should be against allowing trans people to self-identify. Allowing the transgender community to use the bathroom of their self-identity is an attack on religious values. Everybody has the right to believe what their faith teaches. In acknowledging trans rights, we are trampling over the rights of Christians and other faiths to practice their beliefs. If a Christian owns a restaurant, and a transgender customer enters, it is immoral for the business-owner to serve them, let alone permit them to use the bathroom of their choosing..
The religious view of gender and sex is too narrow. It ignores science and cannot adequately explain all aspects of gender and sex. For example, genetic disorders can lead to children being born with both a penis and a vagina. How would religious leaders classify their sex? Their view of sex and gender is too narrow to acknowledge the existence of millions of people around the world which possess both male and female genitalia. Also, Christians assert that if a person was born a certain way, then God intends them to remain that way. Yet, science tells us that even if someone was born anatomically female, their brain function can more closely resemble that of a male. God created our minds and our bodies, therefore, God intentionally created transgender people, and people whose brains identify with a gender which does not match their body..
Religious freedoms protect a person's right to practice their faith unimpeded by the law. Many faiths reject a trans person's right to self-identify. Therefore, protecting the right for trans to self-identify limits religious freedoms.
Many religions reasons for rejecting transgenderism are not consistent or logical.