Judeo-Christian is a term that groups Judaism and Christianity, either in reference to Christianity's derivation from Judaism, both religions' common use of the Torah, or due to perceived parallels or commonalities shared values between those two religions, which has contained as part of Western culture.
The term became prevalent towards the middle of the 20th century in the United States to link broader principles of Judeo-Christian ethics such as the dignity of human life, adherence to the Abrahamic covenant, common decency, and support of traditional family values.
The concept of "Judeo-Christian values" in an ethical (rather than theological or liturgical) sense was used by George Orwell in 1939, with the phrase "the Judaeo-Christian scheme of morals." It has become part of the American civil religion since the 1940s.
The term is used, as "Judæo Christian", at least as far back as in a letter from Alexander M'Caul dated October 17, 1821. The term in this case referred to Jewish converts to Christianity. The term is used similarly by Joseph Wolff in 1829, referring to a style of church that would keep with some Jewish traditions in order to convert Jews.
Use of the German term Judenchristlich ("Jewish-Christian"), in a decidedly negative sense, can be found in the late writings of Friedrich Nietzsche, who emphasized what he saw as neglected aspects of continuity between the Jewish world view and that of Christianity. The expression appears in The Antichrist, published in 1895 and written several years earlier; a fuller development of Nietzsche's argument can be found in a prior work, On the Genealogy of Morality.
Christianity inherits the notion of a "covenant" from Second Temple Judaism, in the form of the Old Testament. Two major views of the relationship exist, namely New Covenant theology and Dual-covenant theology. In addition, although the order of the books in the Protestant Old Testament (excluding the Biblical apocrypha) and the Tanakh (Hebrew Bible) differ, the contents of the books are very similar.
Promoting the concept of United States as a Judeo-Christian nation based upon Judeo-Christian ethics first became a political program in the 1940s, in response to the growth of antisemitism in America. Jews played a small role in that but the rise of antisemitism in the 1930s led concerned Protestants, Catholics, and Jews to take steps to increase mutual understanding and lessen the high levels of antisemitism in the United States.
In this effort, precursors of the National Conference of Christians and Jews created teams consisting of a priest, a rabbi, and a minister, to run programs across the country, and fashion a more pluralistic America, no longer defined as a Christian land, but "one nurtured by three ennobling traditions: Protestantism, Catholicism and Judaism....The phrase 'Judeo-Christian' entered the contemporary lexicon as the standard liberal term for the idea that Western values rest on a religious consensus that included Jews."
Through soul-searching in the aftermath of the Holocaust, "there was a revolution in Christian theology in America. [...] The greatest shift in Christian attitudes toward the Jewish people since Constantine converted the Roman Empire." The rise of Christian Zionism--that is, religiously motivated Christian interest and support for the state of Israel--along with a growth of philo-Semitism (love of the Jewish people) has increased interest among American Evangelicals in Judaism, especially areas of commonality with their own beliefs (see also Jerusalem in Christianity). During the late 1940s, Evangelical proponents of the new Judeo-Christian approach lobbied Washington for diplomatic support of the new state of Israel. The Evangelicals have never wavered in their support for Israel. On the other hand, by the late 1960s Mainline Protestant denominations and the National Council of Churches were showing more support for the Palestinians than for the Israelis. Interest in and a positive attitude towards America's Judeo-Christian tradition has become mainstream among Evangelicals.
The scriptural basis for this new positive attitude towards Jews among Evangelicals is Genesis 12:3, in which God promises that He will bless those who bless Abraham and his descendants, and curse those who curse them (see also "Abrahamic Covenant"). Other factors in the new philo-Semitism include gratitude to the Jews for contributing to the theological foundations of Christianity and for being the source of the prophets and Jesus; remorse for the Church's history of antisemitism; and fear that God will judge the nations at the end of time on the basis of how they treated the Jewish people. Moreover, for many Evangelicals Israel is seen as the instrument through which prophecies of the end times are fulfilled.
Response of Jews towards the "Judeo-Christian" concept has been mixed. In the 1930s, "In the face of worldwide antisemitic efforts to stigmatize and destroy Judaism, influential Christians and Jews in America labored to uphold it, pushing Judaism from the margins of American religious life towards its very center." During World War II, Jewish chaplains worked with Catholic priests and Protestant ministers to promote goodwill, addressing servicemen who, "in many cases had never seen, much less heard a Rabbi speak before." At funerals for the unknown soldier, rabbis stood alongside the other chaplains and recited prayers in Hebrew. In a much publicized wartime tragedy, the sinking of the Dorchester, the ship's multi-faith chaplains gave up their lifebelts to evacuating seamen and stood together "arm in arm in prayer" as the ship went down. A 1948 postage stamp commemorated their heroism with the words: "interfaith in action."
In the 1950s, "a spiritual and cultural revival washed over American Jewry" in response to the trauma of the Holocaust. American Jews became more confident to be identified as different.
Two notable books addressed the relations between contemporary Judaism and Christianity, Abba Hillel Silver's Where Judaism Differs and Leo Baeck's Judaism and Christianity, both motivated by an impulse to clarify Judaism's distinctiveness "in a world where the term Judeo-Christian had obscured critical differences between the two faiths." Reacting against the blurring of theological distinctions, Rabbi Eliezer Berkovits wrote that "Judaism is Judaism because it rejects Christianity, and Christianity is Christianity because it rejects Judaism." Theologian and author Arthur A. Cohen, in The Myth of the Judeo-Christian Tradition, questioned the theological validity of the Judeo-Christian concept and suggested that it was essentially an invention of American politics, while Jacob Neusner, in Jews and Christians: The Myth of a Common Tradition, writes, "The two faiths stand for different people talking about different things to different people."
Law professor Stephen M. Feldman looking at the period before 1950, chiefly in Europe, sees religious conflict as supersessionism:
Once one recognizes that Christianity has historically engendered antisemitism, then this so-called tradition appears as dangerous Christian dogma (at least from a Jewish perspective). For Christians, the concept of a Judeo-Christian tradition comfortably suggests that Judaism progresses into Christianity--that Judaism is somehow completed in Christianity. The concept of a Judeo-Christian tradition flows from the Christian theology of supersession, whereby the Christian covenant (or Testament) with God supersedes the Jewish one. Christianity, according to this belief, reforms and replaces Judaism. The belief therefore implies, first, that Judaism needs reformation and replacement, and second, that modern Judaism remains merely as a "relic". Most importantly the belief of the Judeo-Christian tradition insidiously obscures the real and significant differences between Judaism and Christianity.
Advocates of the term "Abrahamic religion" since the second half of the 20th century have proposed a hyper-ecumenicism that emphasizes not only Judeo-Christian commonalities but that would include Islam as well (the rationale for the term "Abrahamic" being that while only Christianity and Judaism give the Hebrew Bible (Old Testament) the status of scripture, Islam does also trace its origins to the figure of Abraham as the "first Muslim").
Advocates of this umbrella term consider it the "exploration of something positive" in the sense of a "spiritual bond" between Jews, Christians, and Muslims.