Christian Church

==Catholic tradition==
{{See also|Historical development of the doctrine of Papal Primacy}}
The Catholic Church teaches in its doctrine that it is the original church founded by Christ on the [[Apostles in the New Testament|Apostles]] in the 1st century AD.

The encyclical of [[Pope Pius IX]], ''Singulari Quidem'', states: "There is only one true, holy, Catholic Church, which is the Apostolic Roman Church. There is only one See founded on Peter by the word of the Lord [...] Outside of the Church, no one can hope for life or salvation unless he is excused through [[Invincible ignorance (Catholic theology)|ignorance]] beyond his control." 

The papal encyclical ''[[Mystici corporis]]'' (Pope Pius XII, 1943), expresses the dogmatic ecclesiology of the Catholic Church thus: "If we would define and describe this true Church of Jesus Christ—which is the One, Holy, Catholic, Apostolic, Roman Church–we shall find no expression more noble, more sublime, or more divine, than the phrase which calls it 'the Mystical Body of Jesus Christ'." The Second Vatican Council's dogmatic constitution, ''[[Lumen gentium]]'' (1964), further declares that "the one Church of Christ which in the Creed is professed as one, holy, catholic and apostolic, [...] constituted and organized in the world as a society, [[Subsistit in|subsists]] in the Catholic Church, which is governed by the successor of Peter and by the Bishops in communion with him".<ref>[https://www.vatican.va/archive/hist_councils/ii_vatican_council/documents/vat-ii_const_19641121_lumen-gentium_en.html ''Lumen gentium''] {{webarchive |url=https://web.archive.org/web/20140906031754/https://www.vatican.va/archive/hist_councils/ii_vatican_council/documents/vat-ii_const_19641121_lumen-gentium_en.html |date=September 6, 2014 }}, 8</ref><ref>In [https://books.google.com/books?id=j8-GHiYUSX8C&q=Dulles+catholicity The Catholicity of the Church], p. 132, [[Avery Dulles]] noted that this document avoided explicitly calling the Church the "Roman" Catholic Church, replacing this term with the equivalent "which is governed by the successor of Peter and by the Bishops in communion with him" and giving in a footnote a reference to two earlier documents in which the word "Roman" is used explicitly.</ref>

A 2007 declaration of the [[Congregation for the Doctrine of the Faith]] clarified that, in this passage, "'subsistence' means this perduring, historical continuity and the permanence of all the elements instituted by Christ in the Catholic Church, in which the Church of Christ is concretely found on this earth", and acknowledged that [[Grace (Christianity)|grace]] can be operative within religious communities separated from the Catholic Church due to some "elements of sanctification and truth" within them, but also added "Nevertheless, the word 'subsists' can only be attributed to the Catholic Church alone precisely because it refers to the mark of unity that we profess in the symbols of the faith (I believe... in the 'one' Church); and this 'one' Church subsists in the Catholic Church."<ref name="responses">[https://www.vatican.va/roman_curia/congregations/cfaith/documents/rc_con_cfaith_doc_20070629_responsa-quaestiones_en.html Responses to Some Questions Regarding Certain Aspects of the Doctrine on the Church] {{webarchive |url=https://web.archive.org/web/20130813100622/https://www.vatican.va/roman_curia/congregations/cfaith/documents/rc_con_cfaith_doc_20070629_responsa-quaestiones_en.html |date=August 13, 2013 }}</ref>

The Catholic Church teaches that only corporate bodies of Christians led by bishops with valid holy orders can be recognized as "churches" in the proper sense. In Catholic documents, communities without such bishops are formally called [[Ecclesial community|ecclesial communities]].