Why does the Church say she is one, holy, catholic and apostolic?

A sentence of the Nicene-Constantinopolitan Creed

The formula is not a medieval invention nor a late apologetic find: it is a clause of the Symbol of faith that the Church still sings today. In the so-called Nicene-Constantinopolitan Creed, after the articles on the Father, the Son and the Holy Spirit, comes this article on the Church: "I believe in one, holy, catholic and apostolic Church."^[4] In Latin: Et unam, sanctam, catholicam et apostolicam Ecclesiam.

The verb matters. We do not merely say "I believe that a Church exists", as one would note a sociological fact; we say "I believe in" the Church, making these four marks an object of faith. The Catechism stresses this: "It is only faith that can recognize that the Church possesses these properties from her divine source. But their historical manifestations are signs that also speak clearly to human reason."^[5] The marks thus stand at the boundary of faith and reason: believed as a divine gift, observable as signs.

From Nicaea (325) to Constantinople (381): the addition of the marks

One must be precise about the history, for the whole formula is often attributed to the Council of Nicaea. The first ecumenical council, Nicaea (325), convened against Arianism, which denied the divinity of the Son, had drawn up a symbol centered on Christ "consubstantial with the Father", and ended soberly, without developing the article on the Church. It is the First Council of Constantinople (381), convoked notably to defend the divinity of the Holy Spirit against the Pneumatomachians, that completed the Symbol and inserted into it the confession of faith in the Church "one, holy, catholic and apostolic"^[6].

This shift is not insignificant. The four marks appear in the immediate wake of Trinitarian dogma: after confessing one God in three Persons, the Symbol confesses one Church, because, as we shall see, the unity of the Church flows from the very unity of the Trinity. The formula of 381 is therefore no decorative addition: it extends Trinitarian faith into its ecclesial consequence.

The formula of the four marks has a traceable history, from the early Fathers to the Catechism:

Marks, properties: a vocabulary to clarify

Theology uses several words to designate these four attributes, and they are worth distinguishing. We speak of properties when we consider the marks as intrinsic qualities the Church possesses by virtue of her divine institution. We speak of marks (notae, signa) when we consider them as outward, visible signs by which the true Church can be recognized and discerned from counterfeits.

This second usage developed above all in the modern era. Faced with the multiplication of confessions born of the Reformation, each claiming the Gospel, Catholic controversialists sought objective criteria to identify the true Church of Christ. Saint Robert Bellarmine would draw up a famous list, but the four marks of the Creed remain its surest core, because they are not a polemical construction: they have been confessed in the Symbol since 381. Vatican I consecrated this dimension of sign by teaching that the Church, "on account of her admirable propagation, her exalted sanctity and inexhaustible fruitfulness in everything good, her catholic unity and her invincible stability, is herself a great and perpetual motive of credibility and an irrefutable witness of her divine mission"^[7].

Before examining the marks one by one, a frequent misunderstanding must be avoided. When the Church calls herself "holy", the modern listener often hears an arrogant claim: "the Church thinks she is perfect." It is the reverse. The marks are not compliments the institution bestows on itself; they describe what God has made of her.

"The Church does not derive them from herself"

The Catechism roots the marks in the mystery of God, not in the merits of men. The Church is "one by reason of her source" in the unity of the Father, the Son and the Spirit; "one by reason of her Founder", the incarnate Son who reconciled all men through his Cross; "one by reason of her soul", the Holy Spirit dwelling in believers^[8]. Likewise, she is holy because "the Most Holy God is her author; Christ, her bridegroom, gave himself up for her to sanctify her; the Spirit of holiness gives her life"^[9]. The marks are therefore Trinitarian gifts, received, not human performances.

This precision changes everything that follows. If the Church derived her holiness from the virtue of her members, the least scandal would make her lose it. If she derived her unity from the harmony of her faithful, the least quarrel would break it. But because the marks come from Christ and the Spirit, they subsist despite the sins of men, while remaining for them a permanent call to conversion. Gift first, task second.

Signs that speak to reason

The marks are not only believed: they are historically verifiable. A Church that claimed unity while shattering into a thousand irreconcilable fragments, or apostolicity while breaking all continuity with the apostles, would visibly contradict herself. That is why Vatican I saw in the persistence of the marks, across twenty centuries of persecutions, heresies and human weaknesses, a rational motive of credibility: not a compelling demonstration that would abolish faith, but a converging body of signs that makes faith reasonable.

"That they may all be one. As you, Father, are in me and I am in you, may they also be one in us, so that the world may believe that you have sent me." — Jesus, Gospel according to Saint John 17:21^[10]

This prayer of Christ at the hour of his Passion illuminates all the marks: the unity of the Church is ordered to a missionary goal — "so that the world may believe". The marks are not a treasure the Church would keep for herself; they are the conditions of her credibility before the world.

One through her source: the Trinity

The first mark is not rooted in an administrative organization, but in the mystery of God himself. The conciliar decree on ecumenism affirms it: "The highest exemplar and source of this mystery is the unity, in the Trinity of Persons, of one God, the Father and the Son in the Holy Spirit."^[11] The Church is one because God is one. Saint Clement of Alexandria already marveled at this correspondence:

"What an astonishing mystery! There is one Father of the universe, one Word of the universe, and one Holy Spirit, everywhere one and the same; there is also one virgin become mother, and I should like to call her the Church." — Saint Clement of Alexandria, The Paedagogus, I, 6^[12]

The unity of the Church thus flows from Trinitarian unity and from the work of the Son, who "reconciled all men with God by his Cross, restoring the unity of all in one People and one Body"^[13]. That is why this unity is also a reality of the Mystical Body: a single body can have only one life.

The visible bonds of unity

The unity of the Church is not only spiritual and invisible; it is expressed through concrete bonds. The Catechism lists three, over which reigns charity, "the bond of perfection" (Col 3:14)^[14].

These three bonds are not interchangeable with mere friendly affection: they are structural. That is why the Church does not conceive Christian unity as a vague feeling of brotherhood among believers of all persuasions, but as communion "in the profession of one faith, the common celebration of worship and apostolic succession". On the necessity of Peter's ministry to keep this unity, see why is the pope necessary?.

Wounded unity: heresy, schism and separated brethren

Christian history is nonetheless marked by ruptures. The Catechism does not hide them: "In this one and only Church of God from its very beginnings there arose certain rifts", and in the course of the centuries "large communities became separated from full communion with the Catholic Church"^[16]. Theology distinguishes three ways of wounding unity: heresy (obstinate rejection of a truth of faith), apostasy (rejection of the Christian faith itself) and schism (refusal of submission to the Pope or of communion with the members of the Church)^[17].

But here the Catholic Church draws a distinction of charity that is often forgotten. Those who are born today into separated communities and live the faith in Christ "cannot be charged with the sin of separateness"; baptized and believing in Christ, they "have a right to be called Christians, and with good reason are accepted as brothers in the Lord by the children of the Catholic Church"^[18]. Outside the visible boundaries of the Church there exist "many elements of sanctification and of truth"^[19] — that is why the Church speaks of "separated brethren" and not of strangers (see what the Church says about Protestants and about the Orthodox).

Unity therefore remains both an unlosable gift — "we believe that she subsists in the Catholic Church as something she can never lose"^[20] — and a goal toward which the whole ecumenical movement tends, through conversion of heart, common prayer and greater fidelity to the Gospel. This tension is the proper form of the first mark: the Church is one, and she prays to become so fully again.

Holy through her Author, her Spouse and her soul

The second mark is doubtless the most exposed to mockery: how can an institution riddled with scandals dare to call herself "holy"? The Catholic answer does not consist in denying sins, but in specifying where the holiness of the Church comes from. It does not come from the virtue of her members; it comes from God. "The Church is, in the eyes of faith, indefectibly holy. For Christ, the Son of God, who with the Father and the Spirit is hailed as 'alone holy,' loved the Church as his Bride, giving himself up for her so as to sanctify her."^[21]

The holiness of the Church is therefore first objective: it resides in her Head, Christ; in her doctrine, free from error; in her sacraments, which truly communicate grace; in her vocation, which calls all her members to perfection. "On earth, the Church is adorned with a true holiness, although imperfect."^[22] She is holy because she possesses "the fullness of the means of salvation", even when her members use them badly.

"The sinless one made up of sinners"

The Catechism retains a striking formula, which must be properly understood if we are not to stumble: the Church is "the sinless one made up of sinners"^[23]. How can both be held together? Because holiness is not the average moral property of her members, but the life of grace circulating within her:

"The Church is holy, though having sinners in her midst, because she herself has no other life but the life of grace. If they live her life, her members are sanctified; if they move away from her life, they fall into sins." — Paul VI, Credo of the People of God, 19^[24]

Christ, "holy, innocent, and undefiled", knew no sin; but the Church, "embracing sinners in her bosom, is at once holy and always in need of purification, and follows constantly the path of penance and renewal"^[25]. All her members, "ministers included, must acknowledge themselves to be sinners". The holiness of the Church is therefore not disproved by scandals: it is the remedy by which the Church "has the power to heal her children through the blood of Christ and the gift of the Holy Spirit".

The saints and Mary: holiness that shines

If visible proof were needed that the holiness of the Church is not a mere abstract principle, it would be the crowd of saints. By canonizing certain faithful, the Church "recognizes the power of the Spirit of holiness within herself" and holds them up "as models and intercessors"^[26]. The holiness of the Church is measured less by the statistics of her sinners than by the fruitfulness of her saints — it is in them that "her holiness shines forth"^[27].

At the heart of this holiness, one figure already completes what the others hope for. "In the person of the Blessed Virgin the Church already attains the perfection which makes her without spot or wrinkle"^[28]; in Mary, the Church is already "the all-holy". And the soul of this holiness, what makes all the members act, is charity, as Saint Thérèse of Lisieux understood:

"I understood that the Church had a Heart, and that this Heart was burning with love. I understood that Love alone made the members of the Church act, that if Love were to be extinguished, the apostles would no longer preach the Gospel, the martyrs would refuse to shed their blood... I understood that Love contained all vocations." — Saint Thérèse of the Child Jesus, Manuscript B^[29]

What does "catholic" mean?

This is the most misunderstood mark, because the word "catholic" has become, in common usage, the name of one confession among others. Yet its primary meaning is quite different. "Catholic" comes from the Greek katholikos, which means "universal", in the sense of "in accordance with the whole" or "in all its fullness"^[30]. To say the Church is catholic is first to say she is full and universal, before designating a confessional belonging.

The term is ancient: it is Saint Ignatius of Antioch, around the year 110, who gives the first known Christian attestation of it, in a sentence that has become classic:

"Wherever Jesus Christ is, there is the Catholic Church." — Saint Ignatius of Antioch, Letter to the Smyrnaeans, 8, 2^[31]

The double meaning: fullness and universality

The Catechism precisely distinguishes two reasons why the Church is called catholic^[32].

First, by fullness: the Church is catholic "because Christ is present in her" and she receives from him "the fullness of the means of salvation" — a "right and complete confession of faith, full sacramental life, and ordained ministry in apostolic succession"^[33]. In this sense, the Church was already fully catholic "on the day of Pentecost", even though she was contained entirely in a single room in Jerusalem: catholicity, here, is not a question of numbers but of the integrity of the gift received.

Second, by universality: the Church is catholic "because she has been sent out by Christ on a mission to the whole of the human race"^[34]. "Go therefore and make disciples of all nations" (Mt 28:19). Catholicity is then a missionary dynamism: the Church "is, by her very nature, missionary"^[35], destined to expand "to the dimensions of the entire universe and of all ages".

Cyril of Jerusalem: the reasons for a name

As early as the 4th century, Saint Cyril of Jerusalem explained to the catechumens why the Church bears this name, unfolding all the richness of the word:

"Now it is called Catholic because it is throughout the world, from one end of the earth to the other; and because it teaches universally and completely one and all the doctrines which ought to come to men's knowledge; and because it brings into subjection to godliness the whole race of mankind... and because it universally treats and heals the whole class of sins... and possesses in itself every form of virtue." — Saint Cyril of Jerusalem, Catecheses, XVIII, 23^[36]

Catholicity, in Cyril, is thus at once geographical (the whole earth), doctrinal (all truths), social (all men) and moral (all sins healed, all virtues). It is not an identity flag: it is a fullness offered to all.

"Christian my name, Catholic my surname"

Should we then oppose "Christian" and "Catholic", as if the second were a sectarianism added to the first? Tradition answers with the lapidary formula of Saint Pacian of Barcelona, in the 4th century:

"Christian is my name, and Catholic my surname. The one designates me, while the other makes me specific." — Saint Pacian of Barcelona, First Letter to Sympronian, 4^[37]

The "surname" catholic adds nothing foreign to the Christian name: it specifies which Christianity we are speaking of — the one that keeps the whole faith and universal communion, as opposed to the partial Christianities of the sects. To be Catholic is not to be more than Christian; it is to be fully Christian.

The canon of Saint Vincent of Lérins

How can we concretely recognize what belongs to the "catholic" faith, that is, believed everywhere, and what is only a sectarian novelty? Saint Vincent of Lérins, around 434, proposed a criterion that has remained famous, the "Vincentian canon":

"In the Catholic Church itself, all possible care must be taken, that we hold that faith which has been believed everywhere, always, by all." — Saint Vincent of Lérins, Commonitorium, II^[38]

Universality (quod ubique), antiquity (quod semper), general consent (quod ab omnibus): these three criteria do not manufacture truth, but they help discern the doctrine received from the apostles from particular inventions. The catholicity of the faith is thus its extension in space and time: what the Church believes is not the opinion of one school, but the faith of all times and all places.

Catholic does not mean "without doctrinal boundaries"

One clarification is needed to avoid a modern misunderstanding. "Catholic" means "in accordance with the whole" — not "in accordance with just anything". The universality of the Church is not a relativism that would welcome all beliefs: it is the openness to all men of an integral and complete faith. That is why catholicity goes hand in hand with mission: the Church proclaims "the totality of the faith" and "bears within herself and administers the fullness of the means of salvation"^[39], precisely because she has something complete to offer to all. On what becomes of one who seeks God without knowing the Church, see can one be Christian without the Church?.

Built on the foundation of the apostles

The fourth mark anchors the Church in history. She is not a timeless idea nor a community reinventing itself with each generation: she is built on the apostles, those precise men Christ chose and sent. The Catechism specifies that the Church is apostolic "in a threefold sense"^[40].

These three senses hold together. Apostolicity of origin without fidelity to the deposit would be a mere genealogical claim; the deposit without a living succession would remain a dead text. It is the whole — foundation, doctrine, succession — that makes apostolicity.

The bishops, successors of the apostles

The heart of the apostolic mark is apostolic succession: the unbroken transmission of the apostles' charge to their successors. "In order that the mission entrusted to them might be continued after their death, the apostles consigned, by will and testament, to their immediate collaborators the duty of completing and consolidating the work they had begun."^[41] The Church thus teaches that "the bishops, by divine institution, have succeeded to the place of the apostles as pastors of the Church"^[42].

This continuity is not only historical; it guarantees the truth. Through it, the faith received from the apostles is not corrupted in being handed on. The detail of this mechanism — laying on of hands, validity, episcopal lineages — is treated in the dedicated article: why does the Catholic Church speak of apostolic succession?. Let us only say here that it makes the Church a reality "infallibly maintained in the truth", governed by Christ "through Peter and the other apostles, present in their successors, the Pope and the college of bishops"^[43].

Every baptized person is called to the apostolate

Apostolicity, however, is not reserved to the hierarchy. "The whole Church is apostolic, in that she remains, through the successors of St. Peter and the other apostles, in communion of faith and life with her origin: and in that she is 'sent out' into the whole world; all members of the Church, though in different ways, share in this mission."^[44] The Christian vocation is "by its very nature a vocation to the apostolate": every baptized person receives, together with the faith of the apostles, the mission to hand it on.

"Since Christ, sent by the Father, is the source and origin of the whole apostolate of the Church, the success of the lay apostolate depends upon the laity's living union with Christ." — Second Vatican Council, Apostolicam actuositatem, 4^[45]

It is "always charity, drawn above all from the Eucharist, which is as it were the soul of the whole apostolate"^[46]. Apostolicity thus rejoins holiness: the faith of the apostles is truly handed on only by living on the charity of Christ.

One last question, theologically decisive: can one have one mark without the others? The Catechism clearly answers that the four attributes are "inseparably linked with each other"^[47]. One cannot be fully one without being apostolic (unity passes through the succession of the apostles), nor fully catholic without being holy (the fullness of the means of salvation is ordered to sanctification), and so on. The marks form an organic whole: they stand or fall together.

It is this cohesion that makes the four marks, taken together, a "motive of credibility": a single isolated mark could be counterfeited, but their convergence over twenty centuries is a sign reason can weigh. The Church finally confesses that this identity will be fully manifested only at the end of time: she is "one, holy, catholic and apostolic in her deep and ultimate identity" because in her the Kingdom of heaven already exists and will be fulfilled at the end of time^[48].

"The Church is divided: where then is her unity?"

This is the most immediate objection: there are Catholics, Orthodox, Protestants — where is the unity? The Catholic answer distinguishes two things. The unity given by Christ to his Church subsists in an "unlosable" way in the Catholic Church^[49]; what is wounded is not the unity of the Church herself, but the full communion of all Christians with her. The divisions are real and painful, but they do not prove that Christ failed: they manifest the weight of men's sin, against which the Church prays unceasingly "that all may be one".

"With her scandals, how can she be holy?"

This objection confuses the holiness of the Church with the moral perfection of her members. Yet the Church has never claimed to be composed of impeccable people: she knows herself to be "made up of sinners". Her holiness lies in her Author, her doctrine, her sacraments and her saints, not in the average virtue of her faithful or her ministers. Scandals contradict the holiness to which the Church calls; they do not contradict the holiness she receives from Christ. It is even because she is holy that she recognizes sin as sin, does penance and offers forgiveness.

"Doesn't 'Catholic' mean sectarian?"

The objection inverts the meaning of the word. "Catholic" means "universal, in accordance with the whole": it is exactly the opposite of a sect, which defines itself by what it cuts away. The sect chooses a part (hairesis, in Greek, means "choice"); the Catholic Church keeps the whole. Far from a withdrawal, catholicity is the widest possible openness: to all peoples, all times, all truths of the faith. "Christian my name, Catholic my surname", said Pacian: the surname does not narrow the name, it guarantees its fullness.

"Have the other confessions nothing apostolic?"

The Catholic Church does not say that. She recognizes that "many elements of sanctification and of truth" — Scripture, Baptism, faith, grace — exist outside her visible boundaries^[50], and that the Orthodox Churches in particular keep a valid apostolic succession and true sacraments. What she affirms is that the fullness of the means of salvation and the guarantee of unity subsist in the Church governed by Peter's successor^[51]. The four marks do not deny the riches of others: they point to where their source and fulfillment lie.

The four marks of the Church are the key to Catholic ecclesiology: they govern the way we understand the unity of Christians, the holiness of the Institution, her universal mission and her fidelity to the apostles. To explore their ramifications further, see:

• What is the Mystical Body of Christ? — the Church as the living body whose properties the marks are.
• Why does the Church speak of apostolic succession? — the concrete mechanism of the apostolic mark.
• Why is the pope necessary? — the ministry that keeps unity.
• Can one be Christian without the Church? — catholicity and the necessity of the Church for salvation.
• What is the origin of the Catholic Church? — the historical rooting of apostolicity.