[3] The term was similarly used by Joseph Wolff in 1829, in reference to a type of church that would observe some Jewish traditions in order to convert Jews.
[5] Friedrich Nietzsche used the German term "Judenchristlich" ("Jewish-Christian") to describe and emphasize what he believed were neglected aspects of the continuity which exists between the Jewish and Christian worldviews.
The expression appears in The Antichrist, published in 1895 but written several years earlier; a fuller development of Nietzsche's argument can be found in the prior work, On the Genealogy of Morality.
[7] According to historian K. Healan Gaston, the term became a descriptor of the U.S. in the 1930s, when the country sought to forge a unified cultural identity in an attempt to distinguish itself from fascism and communism in Europe.
Becoming part of the American civil religion by the 1940s, the term rose to greater prominence during the Cold War, especially when it was used to express opposition to communist atheism.
[9] 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.
From the 1990s, continuing through the first two decades of the 21st century, interest in and a positive attitude towards America's Judeo-Christian tradition has become mainstream among evangelicals and (to some extent) the political conservative movement in the United States.
[13] Natan Sharansky observed in 2019, that for the first time, he was encountering the situation of nations with ample governmental support for Israel but disinterest and even overt hostility by the Jewish populace.
Other factors in the new philo-Semitism include gratitude to the Jews for contributing to the theological foundations of Christianity and 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 based on how they treated the Jewish people.
"[10] During World War II, Jewish chaplains worked with Catholic priests and Protestant ministers in order to promote goodwill, addressing servicemen who, "in many cases had never seen, much less heard a Rabbi speak before.