The evangelical christians of the United States of America that you are thinking about have nothing to do with this. They are at most offshoot Gnostics. There's a reason why Stalin killed all of them and the Vatican killed all of them way back in Rome.

The actual Christianity back in Ancient Rome? Look at that and you'll see how did we exactly pass off condoning gender fluidity and LGBTQP+ as totally normal. It's exactly the same way they will make changing genders like changing clothes, really.