Union of Scranton in the context of "Polish National Catholic Church"

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.