One true church
The expression "one true church" refers to an ecclesiological position asserting that Jesus gave his authority in the Great Commission solely to a particular visible Christian institutional church—what is commonly called a denomination. This view is maintained by the Catholic Church, the Eastern Orthodox Church, the Oriental Orthodox communion, the Assyrian Church of the East, the Ancient Church of the East, and the Lutheran churches, as well as certain Baptists. Each of them maintains that their own specific institutional church exclusively represents the one and only original church. The claim to the title of the "one true church" relates to the first of the Four Marks of the Church mentioned in the Nicene Creed: "one, holy, catholic, and apostolic church". As such, it also relates to claims of both catholicity and apostolic succession: asserting inheritance of the spiritual, ecclesiastical and sacramental authority and responsibility that Jesus Christ gave to the apostles.
The concept of schism somewhat moderates the competing claims between some churches—one can potentially repair schism, since they are striving for the same goal. For example, the Catholic and Eastern Orthodox churches each regard the other as schismatic and at very least heterodox, if not heretical, yet both have held dialogues and even partaken in Councils in attempts to resolve the division that exists between them.
Many Mainline Protestants regard all baptized Christians as members of a spiritual—not institutional—"Christian Church" regardless of their differing beliefs; this belief is sometimes referred to by the theological term "invisible church". Some Anglicans of Anglo-Catholic churchmanship espouse a version of branch theory which teaches that the true Christian Church comprises Anglican, Eastern Orthodox, Old Catholic, Oriental Orthodox, Scandinavian Lutheran, Moravian, Persian, and Roman Catholic branches.
Restorationist denominations, such as the Church of Jesus Christ of Latter-day Saints also claim inheritance of the authority and responsibility that Jesus Christ conferred on the apostles. Other groups, such as Iglesia ni Cristo, believe in a last-messenger doctrine, where no such succession takes place. The Seventh-day Adventist Church regards itself to be the one true church in the sense of being a faithful remnant.
Teachings by denomination
Catholicism
The Catholic Church teaches that Christ founded only "one true Church", and that this one true Church is the Catholic Church with the bishop of Rome as its supreme, infallible head and locus of communion. From this follows that it regards itself as "the universal sacrament of salvation for the human race" and the "only true religion".According to the Catechism of the Catholic Church, Catholic ecclesiology professes the Catholic Church to be the "sole Church of Christ"—i.e., the one true church defined as "one, holy, catholic, and apostolic" in the Four Marks of the Church in the Nicene Creed. The Council of Nicea originally formulated this teaching and ratified the Nicene Creed. 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, is considered the successor to the apostle Simon Peter, from whom the Pope derives his supremacy over the Church. The 1943 papal encyclical Mystici corporis Christi further describes the Church 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 Humani Generis, Pope Pius XII declared that "the Mystical Body of Christ and the Catholic Church are one and the same thing." The Second Vatican Council repeated this teaching, stating in the Decree on the Eastern Churches: "The Holy Catholic Church, which is the Mystical Body of Christ, is made up of the faithful who are organically united in the Holy Spirit by the same faith, the same sacraments and the same government."
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..." And it also clarified that the term subsistit in used in reference to the Church in the Second Vatican Council's 1964 decree Lumen gentium "indicates the full identity of the Church of Christ with the Catholic Church".
The 1215 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.
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 of 1962–1965 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 Catholic 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.
Catholic theology regards formal schismatics as outside the church, understanding by "formal schismatics" baptized "persons who, knowing the true nature of the Church, have personally and deliberately committed the sin of schism". The situation, for instance, of those who have been brought up from childhood within a group not in communion with Rome, and who are acting in good faith and have maintained almost the entirety of the orthodox faith, differs. This nuanced view applies especially to the churches of Eastern Christianity, more particularly still to the Eastern Orthodox Church, though doctrinal impediments still remain, such as disagreement over the primacy of the Roman See, papal infallibility, the nature of Purgatory, indulgences, the Immaculate Conception, and a few other important doctrines.
Orthodoxy
The Eastern Orthodox Church identifies its confederative communion of Orthodox churches as the "One, Holy, Catholic, and Apostolic Church" of the Nicene-Constantinopolitan Creed and applies this title in conciliar and other official documents, for instance, in the Constantinople synods held in 1836 and 1838 and in correspondence with Pope Pius IX and with Pope Leo XIII.Lutheranism
The Lutheran Church views itself as the "main trunk of the historical Christian Tree" founded by Christ and the Apostles, holding that during the Reformation, the Church of Rome fell away. 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".Lutheran theology therefore holds that:
Laestadian Lutherans, in particular, emphasize this belief.
In the Lutheran Churches, the "Office of the Keys is the special authority which Christ has given to His Church on earth: to forgive the sins of the penitent sinners, but to retain the sins of the impenitent as long as they do not repent." Lutheran doctrine cites as the basis for the sacrament of Confession and Absolution.
Baptists
Many Baptists, who uphold the doctrine of Baptist successionism, "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."