(taken from The Catechism Explained )
When we say, “I believe in the Holy Catholic Church,” we are not speaking of the material church, the place in which we faithful unite to pay God that tribute of love, honor, and attention which we owe to Him, and which is called religion. In this sense “church” means temple, house of God, or house of prayer.
But by those words of the Creed, we affirm belief in the Church as the society or congregation of the faithful, united by the profession of one and the same Faith, united also by participation in the same Sacraments, and by submission to the legitimate prelates, principally to the Roman Pontiff.
Marks of the True Church
Thus it is that it was necessary for God to form Her in such a way that everyone could recognize Her, and that nobody could confuse Her with the synagogue of Satan, the mother of all reprobates.
To this end, He built Her first upon the great mountain of holiness, virtues, and merits of Our Lord Jesus Christ. And, seeing that His enemies would also pretend to come from Him and take His name, in order that even the unlearned would be able to distinguish Her from the pretended and false variety of Christians, He marked Her with four signs so clear that only a willfully blind man would mistake Her. These signs are: One, Holy, Catholic, and Apostolic; I shall proceed to explain them briefly.
In the first place He made it One. Not having more than One God, nor been given more than One Faith, as Saint Paul says, and One Baptism, which is the door of His Church and of the other Sacraments, neither can there be more than One True Religion in which men can please God and accomplish His most holy will. Jesus Christ, Who compares His Church to One fold, did not form various apostleships and gatherings of the faithful. He formed but One assembly and One apostleship, to which He gave not many heads, but One only — that is, Himself as the invisible Head, and Saint Peter and his successors, the Popes, as the visible Head — commanding them to unite all nations within His fold, teaching them all the same law and doctrine.
By this the true Church is distinguished from the synagogues of Satan or heretical sects, of which some teach one thing others another. And what they teach today they reject tomorrow, never agreeing among themselves.
As there cannot be more than One truth, so there can be no true Church except that which, coming from Jesus Christ, has always taught the same Faith, the same law and doctrine; which has always administered the same Sacraments; which has always had only One head, One government, One worship; and which has always been truly One. This alone is sufficient to prove that the true Church is the Catholic Church, in whose society we have the happiness of living.
Holiness, the Second Mark
The second sign God gave to His Church was to make it Holy. A God Who is holiness itself, and Who announced that He would come as the Holy of Holies, could not have made Her otherwise. For this reason, Holy is Her doctrine, Holy the Sacraments She administers, Holy the worship She gives to God, Holy all Her practices, and Holy many of Her members or children.
Consider well, my son, that Jesus Christ came in order to form a society of saints in heaven. And those are not to be few, but many, as it is written: “I saw a multitude of saints, which were innumerable.” For this reason there must always be saints in the true Church. And, actually, there have been, there are now, and there always will be saints in the Catholic Church.
But heretical sects can count not even one, nor will they ever have them. Do you know how they evade this argument? They make fun of the saints and even of the Most Holy Virgin Mary. But they will stop laughing when they are presented to the tribunal of God, where they will find that those Catholics who observed the laws and doctrine taught by our Holy Church are saved — while heretics, even though they observed their own laws, are condemned! Now they will exclaim, but without profit: “We fools esteemed their life [that of the true Catholics] madness and their end without honor. Behold how they are numbered among the children of God, and their lot is among the saints. Therefore have we erred from the way of truth”(Wis. 5:4).
The Church is Universal…
The third character or sign of the Church is to be Catholic — which is to say, Universal — because the prophets already had announced that She must extend Herself throughout all the land.
She is Catholic with respect to time since, having begun in the time of Jesus Christ and with Him, She will last until the end of time, as He Himself promised, and will continue in heaven for all eternity. For this reason no heretical sect can glory in being the true Church. None of them began with Jesus Christ, but came very much later. It is always possible to demonstrate of each one of them the age in which it began by that age in which lived the heresiarch who gave it his name. Likewise, none of them will last to the end of the world. Either they soon die after birth or they change in such a manner that, at the most, they preserve only their original name.
She is Catholic also with respect to places, or to Her reach and diffusion throughout all the world, clasping to Her breast all groups of people without distinction of nations, classes, ages, or sexes. In all times, in all countries, and in all groups of people where She is found, She has held, and will continue to hold, one and the same Faith, one and the same doctrine or morality, and one and the same form of government under the Roman Pontiff. And Her members, wherever they are found, will always be united by the same beliefs, by the same hope, and by charity, being alive by grace. Thus, She embraces all those who are to be saved. For She is another ark of Noah. Outside of the ark everyone drowned in the flood; and so also will everyone drown or be damned who does not choose to enter into this mystical ark, the Church of Jesus Christ. “Who does not have the Church for a mother,” says Saint Cyprian, “cannot have God for a father.”
The fourth note or mark of the Church is to be Apostolic. That is to say, it was founded by the Apostles and is governed by their successors, the bishops, who. since the Apostles, have succeeded without interruption. And these bishops have a lawful mission to guard always, in their teaching and management of the Church, the unity of Faith and of communion with their head and center, the Roman Pontiff.
Listen well, my son, to what Jesus Christ said to the Apostles upon entrusting to them the foundation and government of His Church till the end of the world: “Going therefore teach ye all nations: baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: Teaching them to observe all things whatsoever I have commanded you: and behold I am with you all days, even to the consummation of the world”(Matt. 28:19-20).
All of us know that the Apostles fulfilled the mission that Jesus Christ gave them. And it is sufficient to read the list of the Catholic bishops, especially of the Supreme Pontiffs of Rome as the continuing Head or principal leader of Christianity — better said, of Catholicism — in order to see that
Pius IX, who by the mercy of God happily governs us, have succeeded Gregory XVI, and he Pius VIII. And so, ascending from one to the other, we shall arrive at Saint Peter, who was made by Jesus Christ the Prince of the Apostles and His Vicar on earth.
You will notice above that with the word mission I added the word lawful, that is, coming from that one who has the keys of the kingdom of heaven or of the Church, who is the Pope. Therefore the intruder bishops, or those who have separated themselves from obedience to the Roman Pontiff, are not successors of the Apostles. Rather, they are thieves, as Jesus Christ calls them, and we must flee from them as the sheep flee from the wolves.
If, then, any heretics come to you, my son, saying that their churches are also Apostolic, there is nothing more to say to them than what Tertullian said: “Prove the origin of your churches. Make us see that the order of your bishops has in some way through succession descended from the beginning, that the first was any of the Apostles, or had as a predecessor some of the Apostolic men who had persevered together with the Apostles.”
Inasmuch as the heretical sects will never be able to show this, so it is that none of them can reasonably glory in being Apostolic. But on the other hand, since the Catholic Church is the only one that is able to trace Her origin to the Apostles, it follows from what I have said that She alone is in all truth Apostolic.
Here you have explained for you, my son, the four marks which I told you God left us in order that we may know the true Church. By these we cannot confuse Her with the many synagogues of Satan, which also pretend to be the Church of God. We can see that none are in peace or unity except ours. Furthermore, we can conclude that ours is the only truth, in which and with which we must live and die united in order to be able to go to heaven.
A City on a Mountain
Since the first Head or Leader of Christ’s Church, Saint Peter, fixed his Apostolic chair in Rome, this is why She is called Roman — that is, governed by the Pontiff of Rome, successor of the authority of Saint Peter, and consequently, like him, Vicar of Jesus Christ and Father of all Catholic.
Some heretics, not knowing what to answer Catholics who ask them where their church was before their heresiarch came into the world, slyly suggest that the Church of Jesus Christ was to be invisible. Which is equivalent to saying that the sun, in the middle of a bright day and without an eclipse, can be hidden.
You must realize, my son, that the true Church is necessarily visible. Because visible are the faithful and Her members; visible are the Sacraments which She administers to them; visible are the traditions which form the wise and holy laws that She teaches; visible are the bishops who govern Her under obedience to the Sovereign Pontiff, and visible also is that Supreme Pontiff who rules Her in all his universality and with all the fullness of power.
Besides this, She must be visible because Jesus Christ ordered that cares and complaints be brought to the Church. And as His judgments are to be revered, this order could not be carried out if She were not visible.
The true Church is a city seated on a mountain, of which the holy Evangelist speaks, and therefore, Her visibility must be clearly evident. Consequently, the evasions of the heretics are futile. For this reason you cannot doubt that the only true Church is our Catholic, Apostolic, and Roman Church, in which you must persevere, inwardly and outwardly. And with all preciseness must you observe Her holy laws if you want to save your soul. Otherwise, you will be lost forever.