Source: "THE CATHOLIC DOGMA"
By Michael Müller, C.SS.R
New York, Cincinnati, and Chicago:
Printers to the Holy Apostolic See
Permissu Superiorum, 1888 A.D.
WHAT CATHOLIC FAITH IS.
No one can go to heaven unless he knows the way to heaven. If we wish to go to a certain city, the first thing we do is to ask the way that leads to it. If we do not know the way, we cannot expect to arrive at that city. So, too, if we wish to go to heaven, we must know the way that leads to it. Now, the way that leads to it is the knowing and doing of God's will. But it is God alone who can teach us his will; that is, what he requires us to believe and to do, in order to be happy with him in heaven.
The end for which man was created—his everlasting union with God—says the Vatican Council, is far above the human understanding. It was, therefore, necessary that God should make himself known to man, and teach him the end for which he was created, and what he must believe and do in order to become worthy of everlasting happiness.
"If you wish to judge well of a grand edifice, you must study in detail its form and dimensions; you must examine minutely its style of architecture and strive to comprehend the architect's design. All this will cause you much trouble and impatience, and still your knowledge of the edifice will not be complete.
"But, if the architect himself explains to you his plan, and, in addition to the knowledge you already have of the building, gives you sufficient information of its first cause, then you will be able to give a full, distinct description of the whole edifice.
"In like manner, a learned man may strive on all occasions, and by all natural means in his power, to know the first cause of the grand edifice of creation, its plan and object. All this will give him much trouble, and yet his knowledge of the work of creation will be very incomplete so long as he has not learned its first cause, and plan, and object from the divine Architect himself." (St. Thomas Aquinas.)
Now, God himself, in his infinite mercy, came to tell us why he had created us; he came and taught us the truths which we must believe, the commandments which we must keep, and the means of grace which we must use to work out our salvation.
To know God's will is to know the true religion or the true way to heaven. As God is but one, so his holy will is but one, and therefore his religion is but one and the same. In order that we might learn, with infallible certainty, this one true religion, Almighty God appointed but one infallible teaching authority—the Roman Catholic Church—and commanded all to hear her and believe her infallible doctrine, under pain of exclusion from eternal life.