Answer:
   
   Communism and Marxism are discredited fin-de-siecle (late 19th
   century) atheistic philosophies in which people are grouped by
   economic class, seen as the primary force of history. In contrast,
   Judaism postulates a set of overriding moral principles, which
   traditional Jews believe came from G-d, and recognizes the power of
   righteous and evil individuals.
   
   Humanism places man above all else. Judaism places G-d above all else,
   especially above mankind. "Jewish Humanism" usually describes the
   combination of elements of Eastern European (Jewish) culture and an
   atheistic absolute moral code which just so happens to be very similar
   to Judaism's. For more details, see the [5]Humanistic Reading List.
   
   Judaism rejects the possibility of G-d assuming human form. (See
   Talmud Yerushalmi, tractate Taanis 2:1 (9a) from Bamidbar [Numbers]
   23:19). Judaism also rejects the concept of a mandatory mediator
   between G-d and man, although it accepts the idea that one person can
   petition G-d on behalf of others. Branches of Xianity postulate
   salvation exclusively through faith, while Judaism requires observance
   of the commandments, irrespective of one's level of faith.
   
   For more detail, see question 4 in Prager and Telushikin's [6]The Nine
   Questions People Ask About Judaism (Simon and Schuster, 1981, page 77)