Neo-orthodoxy in the context of "Reinhold Niebuhr"

Friedrich Daniel Ernst Schleiermacher (/ˈʃlaɪərmɑːxər/; German: [ˈfʁiːdʁɪç ˈʃlaɪɐˌmaxɐ]; 21 November 1768 – 12 February 1834) was a German Reformed theologian, philosopher, and biblical scholar known for his attempt to reconcile the criticisms of the Enlightenment with traditional Protestant Christianity. He also became influential in the evolution of higher criticism, and his work forms part of the foundation of the modern field of hermeneutics. Because of his profound effect on subsequent Christian thought, he is often called the "Father of Modern Liberal Theology" and is considered an early leader in liberal Christianity. The neo-orthodoxy movement of the twentieth century, typically (though not without challenge) seen to be spearheaded by Karl Barth, was in many ways an attempt to challenge his influence. As a philosopher he was a leader of German Romanticism.

Liberal Christianity, also known as liberal theology and historically as Christian modernism (see Catholic modernism and fundamentalist–modernist controversy), is a movement that interprets Christian teaching by prioritizing modern knowledge, science and ethics. It emphasizes the importance of reason and experience over doctrinal authority. Liberal Christians view their theology as an alternative to both atheistic rationalism and theologies based on traditional interpretations of external authority, such as the Bible or sacred tradition.

Liberal theology grew out of the Enlightenment's rationalism and the Romanticism of the 18th and 19th centuries. By the late 19th and early 20th centuries, it was characterized by an acceptance of Darwinian evolution, use of modern biblical criticism, and participation in the Social Gospel movement. This was also the period when liberal theology was most dominant within the Protestant churches. Liberal theology's influence declined with the rise of neo-orthodoxy in the 1930s and with liberation theology in the 1960s. Catholic forms of liberal theology emerged in the late 19th century. By the 21st century, liberal Christianity had become an ecumenical tradition, including both Protestants and Catholics.

Rudolf Karl Bultmann (/ˈbʊltmɑːn/; German: [ˈbʊltman]; 20 August 1884 – 30 July 1976) was a German Lutheran theologian and professor of the New Testament at the University of Marburg. He was one of the major figures of early 20th-century biblical studies. A prominent critic of liberal theology, Bultmann instead argued for an existentialist interpretation of the New Testament. His hermeneutical approach to the New Testament led him to be a proponent of dialectical theology.

Bultmann is known for his belief that the historical analysis of the New Testament is both futile and unnecessary, given that the earliest Christian literature showed little interest in specific locations. Bultmann argued that all that matters is the "thatness," not the "whatness" of Jesus, i.e. only that Jesus existed, preached, and died by crucifixion matters, not what happened throughout his life.

Conservative Christianity, also known as conservative theology, theological conservatism, traditional Christianity, or biblical orthodoxy is a grouping of overlapping and denominationally diverse theological movements within Christianity that seeks to retain the orthodox and long-standing traditions and beliefs of Christianity. It is contrasted with Liberal Christianity and Progressive Christianity, which are seen as heretical heterodoxies by theological conservatives. Conservative Christianity should not be mistaken as being necessarily synonymous with the political philosophy of conservatism, nor the Christian right (which is a political movement of Christians who support conservative political ideologies and policies within the realm of secular or non-sectarian politics).

Theological conservatism is found in Roman Catholicism, Eastern Orthodoxy, Oriental Orthodoxy, Protestantism, the Church of the East, Old Catholicism, and throughout all of Mainstream-Nicene Christianity in both Western Christian and Eastern Christian traditions. Within Protestantism, it is largely made up of Evangelical Christianity and Christian Fundamentalism, while the Confessing Movement, Confessionalism, and to an extent Neo-orthodoxy make up the remaining; in Roman Catholicism it is inclusive of Catholics that adhere to Traditionalist Catholicism as well as the Magisterium, Scriptures, and Traditions of the Church at the exclusion of Catholic Modernism and Folk Catholicism; and in Old Catholicism it currently includes the Union of Scranton, those of similar beliefs, and historically the Union of Utrecht until its adoption of theological liberalism. In spite of this, not every community has had a direct connection with the Fundamentalist–Modernist controversy.