Use of word racist in specific case [duplicate]

Solution 1:

Bigot is the term that you're looking for.

bigot: a person who strongly and unfairly dislikes other people, ideas, etc.; especially: a person who hates or refuses to accept the members of a particular group (such as a racial or religious group) - (Merriam-Webster)

Solution 2:

You call them either a biased person or a prejudiced person whose meaning includes racist, sexist, and anti-feminist, etc.

It's best to use the adjective, biased, as bias means:

Tendency to believe that some people, ideas, etc., are better than others that usually results in treating some people unfairly.

Or prejudiced:

having or showing an unfair feeling of dislike for a person or group because of race, sex, religion, etc.

He is biased/prejudiced against race means he is a racist.

Solution 3:

Your third example is best described by the word xenophobe:

A person who is fearful or contemptuous of that which is foreign, especially of strangers or of people from different countries or cultures. (TFD)

A good option for religious prejudice/discrimination is sectarian:

1. A member of a sect.
2. One characterized by bigoted adherence to a factional viewpoint. (TFD)

It is not always applied to religion, but often it is.

Solution 4:

Technically "discrimination on the ground of religion" is not racism, but you will often hear it described as such. A more accurate description is religiously intolerant, although that's a bit of a mouthful.

Dictionary.reference.com describes race (2) as "a group of persons related by common descent or heredity". It can hence be used to mean people with the same skin colour, or people from the same country. So scenarios 2 and 3 would both be appropriate for use of the word racist.

Solution 5:

The other answers have addressed your larger questions, but I thought I would attempt to answer this specific one you asked:

Or are there better fitting words for specific forms of discrimination? Particularly for the first scenario (religion specific racism).

There are a number of terms that describe hatred of a particular religion. For example, the word Islamophobia is specific to the hatred of followers of the Muslim faith. A person who exhibits such hatred would be said to be Islamophobic. I suppose one could also call such a person an Islamophobe though I don't know how common that usage is. (TFD)

Another is the word anti-Semitism which refers to the hatred of followers of Jewish tradition. A person who exhibits this would be called anti-Semetic or an anti-Semite. (MW)