As others have said not, explicitly Christian but not super objectionable. I'm a big fan of the series and still reply the games a few times a year.
Pros:
>higher score for no killing, and can beat games without killing anyone (except for bosses in cutscenes)
>promotes heroism and masculinity
>critiques modern governments, warfare, and philosophies
>anit-nuclear, anti-war message
Cons:
>immodestly dressed women (Quiet especially, but also Eva, Meryl, Naomi, B&B group, plus all the hidden Japanese bikini model posters).
>Atheistic/secular worldview is dominant, don't recall any theological discussion and memes (part of evolutionary theory) are an important plot point
As long as you know what to look past and what to take in I think it's fine.