The UN humans rights are not law in the USA. The first amendment says that the government can't make laws about religion. In the USA, people are free to have whatever religion they want, which is great.

Pointing out that all available research points to some religious claim being wrong is not harassment.

All available research also points man and women are different physiologically, neurologically and psychologically. Yet if one goes around pointing that out to women for no good reason, some people will view such speech as discriminatory and will act accordingly. I don’t necessarily agree with these people, but that’s how it works in practice in many places.

According to US federal laws, religion is a protected class just like gender. You can’t discriminate people based on that, no matter whether you related to government or not.

This is getting off topic. Stating facts about the world is not discriminating. As an employer, I can choose not to hire stupid people.

That depends on the facts, context, audience and other human-related things.

As an employer or anyone at all really, ideally, you should do the right things, where “the right things” is only vaguely defined.

Some of these things are written in laws, regulations, and court decisions. They help when one doesn’t know how to handle certain citations (like this case about religious beliefs of other people): looking for that stuff and simply doing what’s written there is a good strategy to not screw up human interactions too much.

However, many other of these right things aren’t written anywhere, adult people are supposed to already know them somehow. Probably, that’s what called “cultural context”.

All that stuff is weird and often illogical, but that’s how all modern societies have been working for centuries if not millennia.