One true church

Catholic Church

The Catholic Church teaches that Christ intended only "one true Church", and that this Church of Christ uniquely 'subsists in' the Catholic Church It also sees itself as "the universal sacrament of salvation for the human race".

In responding to some questions regarding the doctrine of the Church concerning itself, the Vatican's Sacred Congregation for the Doctrine of the Faith stated, "Clarius dicendum esset veram Ecclesiam esse solam Ecclesiam catholicam romanam..." ("It should be said more clearly that the Roman Catholic Church alone is the true Church..") And it also clarified that the term "subsistit in" used in reference to the Church in the Second Vatican Council's decree Lumen gentium "indicates the full identity of the Church of Christ with the Catholic Church".

One of the earlier councils (the Fourth Lateran Council) declared that: "There is one universal Church of the faithful, outside of which there is absolutely no salvation", a statement of what is known as the doctrine of extra Ecclesiam nulla salus. The Church is further described in the papal encyclical Mystici corporis Christi as the "Mystical Body of Christ".

According to the Catechism, the Catholic Church professes to be the "sole Church of Christ", which is described in the Nicene Creed as the One, Holy, Catholic, and Apostolic Church. This teaching was originally formulated at the Council of Nicea (AD 325) at which time the Apostle's Creed (the basis for the Nicene Creed) had been ratified. The church teaches that only the Catholic Church was founded by Jesus Christ, who appointed the Twelve Apostles to continue his work as the Church's earliest bishops. Catholic belief holds that the Church "is the continuing presence of Jesus on earth", and that all duly consecrated bishops have a lineal succession from the apostles. In particular, the Bishop of Rome (the Pope), is considered the successor to the apostle Simon Peter, from whom the Pope derives his supremacy over the Church. The Church is further described in the papal encyclical Mystici corporis Christi as the Mystical Body of Christ. Thus, the Catholic Church holds that "the one Church of Christ which in the Creed is professed as one, holy, catholic and apostolic ... This Church constituted and organized in the world as a society, subsists in the Catholic Church, which is governed by the successor of Peter and by the Bishops in communion with him."

In the encyclical Mortalium animos of 6 January 1928, Pope Pius XI wrote that "in this one Church of Christ no man can be or remain who does not accept, recognize and obey the authority and supremacy of Peter and his legitimate successors" and quoted the statement of Lactantius: "The Catholic Church is alone in keeping the true worship. This is the fount of truth, this the house of Faith, this the temple of God: if any man enter not here, or if any man go forth from it, he is a stranger to the hope of life and salvation." Accordingly, the Second Vatican Council declared: "Whosoever, [...] knowing that the Catholic Church was made necessary by Christ, would refuse to enter or to remain in it, could not be saved. In the same document, the Council continued: "The Church recognizes that in many ways she is linked with those who, being baptized, are honored with the name of Christian, though they do not profess the faith in its entirety or do not preserve unity of communion with the successor of Peter." And in a decree on ecumenism, Unitatis redintegratio, it stated: "Catholics must gladly acknowledge and esteem the truly Christian endowments from our common heritage which are to be found among our separated brethren. It is right and salutary to recognise the riches of Christ and virtuous works in the lives of others who are bearing witness to Christ, sometimes even to the shedding of their blood. For God is always wonderful in His works and worthy of all praise."

The Church teaches that the fullness of the "means of salvation" exists only in the Catholic Church, but the Church acknowledges that the Holy Spirit can make use of ecclesial communities separated from itself to "impel towards Catholic unity" and thus bring people to salvation in the Catholic Church ultimately. It teaches that anyone who is saved is saved through the Catholic Church but that people can be saved ex voto and by pre-baptismal martyrdom as well as when conditions of invincible ignorance are present, although invincible ignorance in itself is not a means of salvation.

Eastern Orthodox Church

The Eastern Orthodox Church has identified itself as the "one, holy, catholic, and apostolic church" in, for instance, synods held in 1836 and 1838 and in its correspondence with Pope Pius IX and Pope Leo XIII. Some Orthodox hold that there can be a kind of imperfect participation in the Church by those not visibly in communion with it. This is most famously expressed by Bishop Kallistos (Ware) of Diokleia, "We can say where the Church is; we cannot say where she is not."

Lutheran Church

The Augsburg Confession found within the Book of Concord, a compendium of belief of the Lutheran Churches, teaches that "the faith as confessed by Luther and his followers is nothing new, but the true catholic faith, and that their churches represent the true catholic or universal church". When the Lutherans presented the Augsburg Confession to Charles V, Holy Roman Emperor in 1530, they believe to have "showed that each article of faith and practice was true first of all to Holy Scripture, and then also to the teaching of the church fathers and the councils".

Anglican branch theory

Apostolic succession is sometimes seen as one of the essential elements in constituting the one true church, ensuring it has inherited the spiritual, ecclesiastical and sacramental authority and responsibility that Jesus Christ gave to the Apostles.

This is the position of those Anglicans who uphold the branch theory that, "though the Church may have fallen into schism within itself and its several provinces or groups of provinces be out of communion with each other, each may yet be a branch of the one Church of Christ, provided that it continues to hold the faith of the original undivided Church and to maintain the apostolic succession of its bishops."

The Catholic Church and the Eastern Orthodox Church, according to that theory, are the principal branches of the one true Church, along with the Anglican Communion. Those churches, however, reject the theory, as do Anglicans other than the church faction often termed "Anglo-Catholicism". Anglo-Catholicism is a point of view that arose during the nineteenth century's Romantic era and which led to a renewed interest in things Catholic. The English Reformation was imagined by Anglo-Catholics to have been only a temporary and artificial interruption in the Catholic history of English Christianity. Anglicans generally do not subscribe to the idea that their church, with or without any supposed connection to the Roman Catholic and Eastern churches, constitute a "one true Church" to the exclusion of other Christian bodies.

Baptist churches

Many Baptists, who uphold the doctrine of Baptist successionism (also known as Landmarkism), "argue that their history can be traced across the centuries to New Testament times" and "claim that Baptists have represented the true church" that "has been, present in every period of history". These Baptists maintain that those who held their views throughout history, including the "Montanists, Novatians, Patarenes, Bogomils, Paulicians, Arnoldists, Henricians, Albigenses, and Waldenses", were persecuted for their faith, a belief that these Baptists maintain to be "grand distinguishing mark of the true church". In the introduction of The Trail of Blood, a Baptist text that explicates the doctrine of Baptist succession, Clarence Walker states that "The history of Baptists, he discovered, was written in blood. They were the hated people of the Dark Ages. Their preachers and people were put into prison and untold numbers were put to death." J. M. Carroll, the author of the said text The Trail of Blood, also appeals to historian Johann Lorenz von Mosheim, who stated "Before the rise of Luther and Calvin, there lay secreted in almost all the countries of Europe persons who adhered tenaciously to the principles of modern Dutch Baptists." Walter B. Shurden, the founding executive director of the Center for Baptist Studies at Mercer University, writes that the theology of Landmarkism, which he states is integral of the history of the Southern Baptist Convention, upholds the ideas that "Only Baptist churches can trace their lineage in uninterrupted fashion back to the New Testament, and only Baptist churches therefore are true churches." In addition Shurden writes that Baptists who uphold successionism believe that "only a true church-that is, a Baptist church-can legitimately celebrate the ordinances of baptism and the Lord's Supper. Any celebration of these ordinances by non-Baptists is invalid."

Baptists who uphold this ecclesiology also do not characterize themselves as being a Protestant Church due to their belief that "they did not descend from those churches that broke away in protest from the church of Rome. Rather, they had enjoyed a continuous historical existence from the time of the very first church in the New Testament days." These views are generally no longer widely held in the Southern Baptist Convention although they are still taught by some Southern Baptist Churches and many independent Baptist churches, Primitive Baptists, and some "congregations affiliated with the American Baptist Association."

Seventh-Day Adventist Church

The Seventh-Day Adventist Church (SDA Church) holds itself to be the one true Church. It specifically teaches that it is the "it is the 'final remnant' of His true church [spanning] the centuries". Seventh-day Adventist eschatology promulgates the idea that in the end times, there will be an "growing opposition between the 'true' church and the 'apostate' church." According to Seventh-day Adventist theology, these apostates are referred to as "Babylon", which they state is an amalgam of religions (including other Christian denominations) that worship on the Lord's Day (Sunday) rather than the Sabbath (Saturday). The SDA Church, in their view, "has drawn substantially on the biblical text, especially the books of Daniel and Revelation, to argue for its own status as the true remnant church which has a divine commission both to exist and to preach its apocalyptic message to the world at large."

Restorationist churches

Restorationism is a broad category of churches, originating during the Second Great Awakening, that characterize themselves as a return to very early Christianity after the true faith was lost in a Great Apostasy. Prominent among these groups are the Churches of Christ (Stone-Campbell movement) and the Latter Day Saint movement (Mormonism). The idea of "restoration" was a popular theme of the time of the founding of these branches, and developed an independent expression in both. In the Stone-Campbell movement, the idea of restoration was combined with Enlightenment rationalism, "precluding emotionalism, spiritualism, or any other phenomena that could not be sustained by rational appeals to the biblical text."

Latter Day Saint movement

In 1830, Joseph Smith established the Church of Christ as a restoration of original Christianity, and in 1831 declared it to be "the only true and living church upon the face of the whole earth". Smith later reported that during his First Vision in his teenage years, Jesus had told him that all churches that then existed "were all wrong; [and] that all their creeds were an abomination in his sight". The Latter Day Saints combined their religion with "the spirit of nineteenth-century Romanticism" and, as a result, "never sought to recover the forms and structures of the ancient church as ends in themselves" but "sought to restore the golden age, recorded in both Old Testament and New Testament, when God broke into human history and communed directly with humankind."

The predominant organization within the movement is the LDS Church, which continues to teach that it is "the only true and living church upon the face of the whole earth". The church teaches that all people who achieve the highest level of salvation must be baptized into the LDS Church; however, those who missed that opportunity in their lifetime may be included through a proxy baptism for the dead, in which a worthy Mormon is baptized on their behalf inside a church temple.

Most other Latter Day Saint churches claim to be the rightful continuation or successor of the church Smith established and therefore claim to be the one true church. However, the Community of Christ, the second-largest Latter Day Saint church, has recently de-emphasized this belief in favor of a position that the Community of Christ "is part of the whole body of Christ". The church's canonized Doctrine and Covenants continues to contain the declaration that the church is the "only true and living church".

Iglesia ni Cristo

The Iglesia ni Cristo (INC), like other restorationist groups, believes that it is the one church founded by Jesus. Adherents hold that the Iglesia ni Cristo ("Church of Christ" in Tagalog) is the only true church of Jesus Christ as restored by Felix Manalo. The church recognizes Jesus Christ as the founder of the Christian Church. Meanwhile, its reestablishment is seen as the signal for the end of days. They believe that the church was apostatized by the 1st or 4th century due to false teachings. The INC says that this apostate church is the Roman Catholic Church.

Fear not for I am with you; I will bring your descendants from the east, And gather you from the west; I will say to the north, 'Give them up!' And to the south, 'Do not keep them back!' Bring My sons from afar, And My daughters from the ends of the earth.

Members believe that the Iglesia ni Cristo is the fulfillment of the passage above. Based from their doctrines, "ends of the earth" pertains to the time the true church would be restored from apostasy and "east" refers to the Philippines where the "Church of Christ" would be founded. The INC teaches that its members constitute the "elect of God" and there is no salvation outside the INC. Faith alone is insufficient for salvation. The Iglesia ni Cristo says that the official name of the true church is "Church of Christ". The two passages often cited by INC to support this are Romans 16:16 "Greet one another with a holy kiss. All the churches of Christ greet you" and the George Lamsa translation of Acts 20:28: "Take heed therefore ... to feed the church of Christ which he has purchased with his blood."