The concept of Revelation presupposes the concept of Magisterium

If God chose to make himself known in History through Revelation, it was logically necessary that he would have also provided the temporal means to preserve this Revelation from being misinterpreted and altered through the vicissitudes of human history. The concept of Revelation therefore presupposes the concept of Magisterium, as Cardinal John Henry Newman explained so well, noting moreover that the Catholic Church has always offered such a Magisterium, and is the only one of all world religions claiming to be divinely revealed, to have always done so.

St Peter's Basilica, Vatican City, Rome / Unsplash / Simone Salvodi

Reasons to believe:

Jesus didn't write anything himself: he only left us the Church as a compass to guide us towards the Kingdom of Heaven.

Jesus did in fact establish a Magisterium by sending his Spirit at Pentecost to Peter and the apostles(Acts 1:5; 2:4), whom he had previously "called" (Mt 10:1), "instituted"(Mk 3:14) and established"(Mk 3:16) "to be with him" (Mk 3:14) throughout his three years of public life, in order to make them his "witnesses" (Lk 24:48) and the foundation of the Church, before promising them: "I will be with you always, to the end of the age" (Mt 28:20).

Such a Magisterium and such promises are indeed logically indispensable if there is a Revelation, in order to prevent human interpretations and opinions from deviating from the message and diluting its substance from the second generation onwards.

History shows that, of all the religions that claim to be revealed (Jewish religion, Christianity, Islam, Brahmanism, Zoroastrianism, Scientology, Unification Church, Raëlianism, Baháʼí Faith, Krishnaism, etc.), only Catholicism has developed this concept of Magisterium around an uncontested leader, the Pope.

Summary:

Cardinal John Henry Newman was originally an Anglican priest, but in 1845, following his study of the Church Fathers, he converted to Catholicism, which he now considered to be the most faithful to the roots of Christianity. In the same year he also published An Essay on the Development of Christian Doctrine, in which he explains, in section II of chapter II, entitled "On the probability of a developing authority in Christianity", that, if there is a Revelation, a Magisterium is absolutely necessary to preserve it over time; otherwise, sooner or later, it will inevitably be distorted and lost: "either an objective revelation has not been given, or it has been provided with means for impressing its objectiveness on the world."

Newman explains in the previous section (I) that our understanding of Revelation cannot be immediate or complete, but must necessarily be the subject of progressive development: "when we turn to the consideration of particular doctrines on which Scripture lays the greatest stress, we shall see that it is absolutely impossible for them to remain in the mere letter of Scripture, if they are to be more than mere words, and to convey a definite idea to the recipient. When it is declared that "the Word became flesh," three wide questions open upon us on the very announcement. What is meant by "the Word," what by "flesh," what by "became"? The answers to these involve a process of investigation, and are developments. Moreover, when they have been made, they will suggest a series of secondary questions; and thus at length a multitude of propositions is the result, which gather round the inspired sentence of which they come, giving it externally the form of a doctrine, and creating or deepening the idea of it in the mind."

The following section (III) explains that this authority has indeed been given to us, and that it resides in the Catholic Church, the depositary of the apostolic succession: "Revelation is a heavenly gift, He who gave it virtually has not given it, unless He has also secured it from perversion and corruption, in all such development as comes upon it by the necessity of its nature"; This leads him to declare that the solution is to be found "in the authoritative seats and homes of old tradition, the Latin and Greek Churches", before going on to show that the contemporary Catholic Church is indeed the heir to this tradition.

Philippe Coueignoux

Beyond reasons to believe:

The logic of Revelation, which leads us to trust the Magisterium founded by Christ, gives us the assurance of the solidity of the Christian faith. This is why it is possible and reasonable to build one's life on this rock (cf. Mt 7:24-27).

Going further:

Full text of John Henry Newman's An Essay on the Development of the Christian Doctrine.

More information:

By What Authority? An Evangelical Discovers Catholic Tradition by Mark Shea (2013)
Article by F.K. Bartels: "Tradition, Scripture, and Magisterium: The Fullness of Truth"
Book by Avery Cardinal Dulles Magisterium: Teacher and Guardian of the Faith (2010)