I am wondering about developed countries in general, but my experience (and the focus of this question) is the USA and Canada.
There are laws in place to prevent discrimination. It is illegal, for example, to deny service to someone because of their skin color.
But what I don't understand, is why those discrimination laws also apply to religion? For example, denying service to someone because they are a Jew is also illegal.
If you were to deny service to someone for being a flat earther, or an asshole, or a known felon, I don't think there is any law that would stop you. Yet all three of those things, like religion, is not something anyone is born with (unlike race or sexuality), but a choice.
I am well aware that in some countries, religion is not a choice. You could be put to death if you decided to be an atheist or a catholic in many countries, for example. But in the US and Canada, nobody can force anyone to be religious, except maybe for your parents until you become old enough to move out.
What I am wondering specifically is what is the justification used to separate certain beliefs (flat earth) from others (religions), and why is it legal to discriminate against one but not the other?
Sometimes discrimination against religions even qualifies as racism (anti-semitism is described as a subset of racism in the answers to this question, and discrimination against Islam is usually described as racism in America), but it is obvious that religions are not races, so why is that?
I do not condone any discrimination whatsoever, but I just don't understand the reasons behind the laws being the way they are at the moment.