The radical Left hates Christianity and Judaism because they promote Western values, and according to many religious people, are fundamental to Western values. They embrace Eastern religions and Islam because they are largely strongly anti-American as expressed by their most vocal advocates.

For some odd reason we don't see a heck of a lot of coverage of more moderate Muslims, American citizens and otherwise, who have always supported America, and still do. Heck, you don't see much coverage of liberals with strong Christian or Jewish beliefs either, although they certainly exist in great numbers.

The hostility towards Western religion does not now, nor ever did, have anything to do with the First Amendment and separation of church and state. The Left doesn't give a rat's ass about the Constitution. That's just a convenient weapon for attacking mainstream American religious values expressed in public.