I would capitalize it, simply because it is a proper noun. This basically means there are not several "creationisms", but one (though there can be variations on the basic beliefs).
In Germany: yes, since it is a noun. Otherwise, since it is no more than a term indicating a particular set of belief-systems, one does not need to capitalize the word.
The word evolution does not need to be capitalized.
No, coral does not need to be capitalized.
No, circa does not need to be capitalized.
No, it doesn't need to be capitalized.
No, it shouldn't be capitalized.
No, kinetic energy doesn't need to be capitalized.
No. Queries do not need to be capitalized.
it does not need to be capitilized.
Yes, acronyms are typically capitalized.
No, the word "revivalist" does not need to be capitalized unless it is at the beginning of a sentence or part of a proper noun.
No it shouldn't be capitalized.