How would this work in practice though? Islam calls the murder of all non-Muslims and I don't recall Islam being illegal in the UK.

@Starship It's the belief of the specific person that matters. The vast majority of Muslims do not believe it is acceptable to murder people. If a specific Muslim did believe that, and was discriminated against for that reason, then it may not be unlawful per Grainger.

What if a Muslim said I believe in the Quran or I follow the Quran and they were discriminated against for that?

@Starship There would be unlawful discrimination because Islam is a recognised religion and it's not viewed as being unworthy of respect in a democratic society etc.

How/Why is Islam, a religion which calls for the killing of all non-muslims, more worthy of respect in a democratic society than a religion which calls for the killing of all homosexuals? Those sound equally bad to me (maybe Islam is even less worthy of respect because it wants to kill more people).

@Starship Established mainstream religions are automatically protected because the full phrase is "religion or belief". If you generically state that you are a Muslim, that's protected. If you state that you're a Muslim and you believe murder is acceptable then that's unlikely to be protected. Again, it's the specific belief in the person's mind that counts, not what the Quran says. Also, your claim about the Quran is highly contentious and most Muslims do not believe it states that you can indiscriminately murder people.

@Starship Most Muslims believe the verse calling for killing non-believers was written in the context of being at war, not during times of peace. I'm not professing to be an expert in Islam so I don't have much more to say about that. In any case, as I've said, it's the belief of the specific person that matters, and most Muslims do not believe that it's ok to murder people, regardless of what is written in the Quran and how you think that should be interpreted.

How is one releastically supposed to know someone's belief? You can only know what they say, and if someone says I believe in the Quran/Islam, they are presumably saying that they agree with it. Hence, wouldn't a person who inteprets the Quran as calling ofr murder be allowed to discriminate against a Muslim (in absence of the Muslim saying they don't think murder is ok)

@Starship, are you Elon Musk?

@Starship No, because the discriminator's interpretation of the Quran is not a relevant factor when the court is deciding if the discrimination was unlawful. It doesn't matter what the discriminator thought; it only matters what the person being discriminated against believes. As for "how are you supposed to know what they believe?" - that's a problem for the court to figure out, and it's not unique to equality law: the court often has to work out what was in a person's mind. They will look at what was said, the person's witness testimony, etc.

@MichaelHarvey Uhh...no Why do you think that? The username?

@Starship Also, in your example of the employee who believes in killing homosexuals but might be making it up, it's not going to be a contested issue. That's because the first Grainger criterion is: "The belief must be genuinely held". In order for the employee to bring a case against the employer, he is by definition stating that it was genuine. Conversely, the employer is arguing that they legitimately discriminated against that belief, so neither side is going to be arguing that the belief was made up.

@Starship "How do you prove a fact at issue in litigation?" law.stackexchange.com/questions/86825/…

@Starship simply finding outrageous claims in a religious scripture isn't sufficient to establish that as current belief of all of the adherents. For good, and for ill, believers pick and choose which parts of their scripture bind them, or are applicable to in the current world.

The Old Testament contains similar admonitions about homosexuality and situational endorsements of rape and murder. You can find a few believers that still hold those to be binding and chafe at the societal standards that forbid them, but many have developed elaborate theological arguments why they are no longer binding. And of course, most simply ignore them and focus on the sections that fit in with current societal beliefs.