I am often asked what are some of the differences between modern Judaism and Christianity. Granted, this is a very complicated topic. Linguistically speaking, Christianity didn’t exist in the first century. Judaism in the first century was not seen as a single “way.” Thus, there were were many Judaisms (i.e.,the Sadducees, the Pharisees, Essenes, Zealots). The followers of Jesus are referred to as a “sect” (Acts 24:14;28:22); “the sect of the Nazarenes”(24:5). Hence, the first followers of Jesus were considered to be a sect of Second Temple Judaism.
But here are some of the differences between Judaism and Christianity: Adapted from 60 Questions Christians Ask About Jewish Beliefs and Practices by Michael L. Brown, pgs 49-53.
1. God—Judaism believes in God’s absolute unity; Christianity believes in God’s tri-unity. Judaism believes that it is acceptable for Gentiles to worship God as Trinity but states that for a Jew, it is idolatrous, especially since this includes the worship of Jesus. Judaism emphasizes God’s complete incorporeality (i.e., that He has no bodily form of any kind); Christianity puts less emphasis on His incorporeal nature.
2.Messiah—Judaism believes that the Messiah, who will be fully human, is yet to come, although there are Jewish traditions that indicate that there is a potential Messiah in each generation. This Messiah will regather the Jewish exiles, fight the wars of the Lord, rebuild the Temple in Jerusalem and bring about universal peace and the knowledge of God. Christianity believes that the Messiah, who was both fully human and fully divine—the Word incarnate, the Son of God—came two thousand years ago to die for our sins, rising from the dead and sending God’s Spirit to the earth to continue His mission. He will return at the end of the age to establish His Kingdom on the earth, destroy God’s enemies and bring about universal peace and the knowledge of God.
3. Sin—Judaism believes that every human being has a battle between the good inclination (the yetzer hatov) and the evil inclination (the yetzer hara’), but it does not believe in the doctrine of “original sin,” emphasizing instead that through the power of repentance, the evil inclination can be overcome. Christianity believes that Adam’s fall affected the entire human race (this, too, is believed by Judaism, but not in as radical a way), that the best of us fall infinitely short of God’s glory and perfection and only through the blood of Jesus, the Messiah, can we be spiritually transformed.
4. Salvation—Judaism does not hold to the concept of individual salvation, and in the late 1970s, when a major Christian organization launched the evangelistic “I Found It” campaign, an Orthodox Jewish rabbi—with whom I attended graduate school classes at New York University—launched the “We Never Lost It” campaign. Judaism thinks more corporately than does Christianity, and even though the concept of forgiveness of sins and atonement is important (see the next paragraph), there is no such concept of “being saved” or “getting saved” in Judaism, and there is much less emphasis on the afterlife (see also the next two entries).
5. Atonement—Although traditional Jews pray daily for the rebuilding of the Temple and the restoration of animal sacrifices (Reform Jews have removed such petitions from their prayer book), Judaism does not believe that blood atonement is essential for personal atonement. Rather, repentance, good deeds, prayer and personal suffering (seen, at times, as a payment for sin) take the place of sacrifices; partial support for this is found in 2 Chronicles 7:14, among other verses. Christianity teaches that atonement can only come through the substitutionary death of the Messiah and that true saving faith includes repentance (see Acts 2:38; 20:21; 26:20).
6. Afterlife—While Judaism recognizes that this world is the vestibule to the world to come, and while there is daily prayer for the coming of the Messiah and the Messianic age, the primary emphasis in Judaism is on the present world, the here and now, in keeping with the emphasis in the Tanakh. Christianity sees the world to come—specifically, heaven and hell—as being of paramount importance, to the point that the way we are called to live in this world can only make complete sense in the light of eternity. While there is a wholesome appreciation of life in this world, it is not to be separated from the world to come.
7. Creed vs. Deed—Judaism has basic creeds—most notably Moses Maimonides’s Thirteen Principles of Faith, although some of these were hotly disputed in his day—and there are fundamental, essential beliefs in Judaism. The greater emphasis, however, is put on deeds—specifically, observing the commandments of the Torah, as understood and passed on through the traditions. Christianity puts a tremendous emphasis on good works and stresses the importance of a transformed life, but its greater emphasis is put on holding to the essentials of the faith, from which a transformed life and good works will naturally emanate. Thus it is sometimes said that Judaism emphasizes orthopraxy; Christianity emphasizes orthodoxy. Or, put another way, Judaism is the religion of the deed, Christianity the religion of the creed. These statements are, however, somewhat exaggerated.
8. Mission—Both Jews and Christians feel a calling to be a light to the world and to make God known, but that sense of mission is worked out very differently in Judaism and Christianity. The former places its emphasis on being faithful to the Jewish calling, meaning living according to the Torah and rabbinic traditions, praying the communal prayers and studying the sacred texts. In so doing, the example of the Jewish people will ultimately enlighten the world. Christianity feels a sacred calling to make the message of salvation known through all available means, including living a life deeply devoted to the Lord (and thereby being an example and hastening redemption) and, quite pointedly, sharing the Good News about Jesus to everyone. Thus, Christianity has always had “missionaries,” while that has not been the norm for more than 1,900 years in Judaism.