The infallibility of the Church is the belief that the Holy Spirit preserves the Christian Church from errors that would contradict its essential doctrines. It is related to, but not the same as, indefectibility, that is, "she remains and will remain the Institution of Salvation, founded by Christ, until the end of the world." The doctrine of infallibility is premised on the authority Jesus granted to the apostles to "bind and loose" (Matthew 18:18; John 20:23) and in particular the promises to Peter (Matthew 16:16–20; Luke 22:32) in regard to papal infallibility. Infallibility of the ecumenical councils The Roman Catholic Church holds this doctrine, as do most or all Eastern Orthodox theologians. However, the Eastern Orthodox churches accept only the Seven Ecumenical Councils from Nicaea I to Nicaea II as genuinely ecumenical, while Roman Catholics accept twenty-one. Only a very few Protestants believe in the infallibility of ecumenical councils, and these usually restrict infallibility to the Christological statements of the first seven councils. Lutheran Christians recognize the first four councils, whereas most High Church Anglicans accept all seven as persuasive but not infallible. A popular view among Eastern Orthodox Christians, especially Greek Orthodox and churches that fall within the Ecumenical Patriarchate, is that an ecumenical council is itself infallible when pronouncing on a specific matter such as Christology, whereas others hold that a council can be considered of full ecumenical authority only once its declarations have been embraced by the faithful, an opinion more common among the Slavic Churches, such as the Russian Orthodox. Catholic Church Catholicism teaches that Jesus Christ, "the Word made Flesh" (), is the source of divine revelation and, as the Truth, he is infallible. The Second Vatican Council states, "For this reason Jesus perfected revelation by fulfilling it through His whole work of making Himself present and manifesting Himself: through His words and deeds, His signs and wonders, but especially through His death and glorious resurrection from the dead and final sending of the Spirit of truth." (Dei verbum, 4). The content of Christ's divine revelation is called the deposit of faith, and is contained in both sacred scripture and sacred tradition, not as two sources but as a single source. A document signed by then-Cardinal Ratzinger and Cardinal Bertone speaks of Of the ordinary magisterium, the Second Vatican Council said: "Bishops, teaching in communion with the Roman Pontiff, are to be respected by all