What must we believe to be saved? from McHugh and Callan’s Moral Theology, 1958

“Without faith it is impossible to please God.”

Image: John Martin’s Last Judgment Wiki Commons CC

Editor’s Notes

I recently shared the Simple Summary of the Catholic Faith written to help my recently deceased Grandmother when she was being received into the Church.

I hope that that document will be useful to others. As I stated, it was intended as a rudimentary summary of the Catholic religion to help prepare the ground for a very elderly person being received into the Church. It was not intended as a defence of the Church’s claims, or a detailed explanation of the points.

But this topic gives rise to some interesting questions. We all know that faith is not sufficient to be saved, and that we must die in a state of grace. That said:

  • How much are Catholic laymen required to know of the Faith, in general?
  • How much are Catholic laymen required to know, in order to receive the sacraments?
  • How much is someone required to know, in order to be received into the Church?
  • What truths are really essential to be believed, in order to attain salvation?

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In order to provide some answers, here are some relevant sections from McHugh and Callan’s Moral Theology.

The Four Mysteries

The answers to the question of salvation – as well as reception into the Church, when circumstances are pressing – turns around what are sometimes called “the four mysteries.” In the words of the extract below, they are:

  1. God’s existence, as the supernatural End or happiness of man, and
  2. His providence as exercised in supplying the means necessary for supernatural salvation
  3. That in God, who is our beatitude, there are three persons (the Trinity), and
  4. That the way to our beatitude is through Christ our Redeemer (the Incarnation).

McHugh and Callan state that the majority of theologians hold that all four mysteries must be held explicitly, but that others hold that the Trinity and the Incarnation can be believed implicitly with the first two. The extract below gives an overview of this interesting topic and debate, as well as explaining the degree to which each mystery should be understood.

Naturally this refers to adults with reason – not to infants or those who have never attained reason.

Urgent real-life applicability

This has practical implications. Imagine that you’re with someone who’s dying, and he says that he wants to make his peace with God.

Are we clear on what are the key things that we need to help him believe, in order for him to save his soul?

As McHugh and Callan point out, at least two (if not all four) of these points are necessary preconditions for implicit faith, which is in turn a precondition for making a supernatural act of contrition.

The excerpts are from McHugh and Callan’s sections:

  • The Virtue of Faith – which details the difference between explicit and implicit faith
  • The Acts of Faith – which details the four mysteries and the related discussion, along with the degree of knowledge required for salvation and in pressing circumstances
  • The Commandment of Knowledge of Faith – which details the degree of knowledge required for laymen in general.

From: McHugh & Callan – Moral Theology – A Complete Course Based on St. Thomas Aquinas and the Best Modern Authorities (and for UK readers). Online at Project Gutenberg and the Internet Archive here and here.

The Virtue of Faith

763. Faith is divided into explicit and implicit, according as the object believed is unfolded or not to the mind.

(a) Faith is explicit regarding any truth, when assent is given to that truth as known in itself and expressed in terms proper to itself. Example: He has explicit faith in the Eucharist who has been instructed concerning the meaning of the mystery, and who assents to it according to that distinct knowledge.

(b) Faith is implicit regarding any truth, when that truth is not known or not accepted in itself, but is accepted in another truth. Example: He has implicit faith in the Eucharist who has not yet heard of it, but who accepts all the teachings of the Church, even those he does not know.

764. Faith is implicit as follows:

(a) Improperly, faith is implicit, if one does not give assent, but is prepared to give it, if necessary, or wishes to give it. These pious dispositions are not the act of faith itself, but they are its beginnings, or preparations leading up to it; they are good, but not sufficient. Example: A pagan who says he would accept the Christian creed, if he thought it were true, or who wishes that he could believe it.

(b) Properly, faith is implicit, if one gives assent to a truth by accepting another in which it is contained, as a particular is contained in a universal (e.g., he who explicitly accepts all the truths of Christianity, implicitly accepts the Eucharist, even when in good faith he thinks it is not revealed), or as an instrument is involved in its principal cause (e.g., he who explicitly believes in the Redemption implicity believes in Baptism, which is the instrument by which Redemption is applied), or as means are contained in their end (e.g., he who explicitly believes that eternal life is a reward, implicitly believes that good works must be performed as a means to that end), or as the reality is expressed in the figure (e.g., those in the Old Testament who explicitly believed in the Paschal Lamb, implicitly believed in the sacrifice of Christ of which the Paschal Lamb was the figure), or as the assent of the disciple is bound up with the assent of the teacher (e.g., the child who explicitly accepts as true the doctrines of faith taught by his pastor, implicitly believes the sense and implications contained in the latter’s instructions).

765. The points about which explicit faith is required can be reduced to four heads (see Catechism of the Council of Trent). These heads are:

(a) The things to be believed: “Preach the Gospel to every creature. He that believeth shall be saved” (Mark, xvi. 15). The Gospel doctrine is summarized in the Apostles’ Creed;

(b) The things to be done: “Teach them to observe all things whatsoever I have commanded you” (Matt., xxviii. 20). The Ten Commandments (see Vol. II) are called the epitome of the whole law;

(c) The ordinances to be observed; “Baptize them in the name of the Father, and of the Son, and of the Holy Ghost” (Matt, xxviii. 19). The Seven Sacraments are the sacred instruments through which the merits of the Passion of Christ are applied to the soul;

(d) The petitions to be made to God: “Thus shall you pray: Our Father, etc.” (Matt., vi. 9). The prayer (see Vol. II) given us by Christ teaches us both the manner of prayer and the requests that should be offered.

766. Faith in the revelation given by God is necessary for salvation (Heb., xi. 6), but in the usual providence of God faith cannot be had or safeguarded without short formulas of its principal doctrines.

(a) Faith cannot be received without such formulas, because, its doctrines being many and frequently difficult and the study of all scripture and Tradition being impossible for most persons, a list of short and clear propositions of revealed truths (Creed) is needed that the faith may be proposed and accepted.

(b) Faith cannot be retained without such formulas, because, being unchanging in itself and yet for all times and places, its doctrines would be easily corrupted if there were not an official standard (Symbol) by which both truth and error could be at once recognized (I Cor., i. 10; II Tim., i. 13).

767. The formulas of Christian teaching as summarized in the Creeds, since they must be brief and orderly, are divided into short and connected propositions, which are therefore known as articles. Brevity being the character of Creeds, not all revealed truths are expressed in them as articles, but only those that have the following characteristics:

(a) An article of the Creed deals with one of the two main objects of belief, namely, the end of man, which is eternal life (Heb., xi. 1), and the means thereto, which is Jesus Christ (John, xvii. 3). Other things, which are proposed for faith, not for their own sake, but only on account of their relation to these two main objects (e.g., the wandering of the Israelites in the desert, the details of the journeys of St. Paul, etc.), are not mentioned in the Creeds.

(b) An article of the Creed deals only with those doctrines concerning eternal life and Christ which are in a special manner unseen or difficult, for faith is “the evidence of things that appear not” (Heb., xi. 1). Other doctrines which have no special difficulty of their own are considered as implicit in those that express the general mysteries, and hence they are not mentioned.

Thus, the three Persons of the Trinity are given distinct articles, because the mysteriousness of the Triune God cannot be reduced to any more general mystery, whereas the Eucharist is not mentioned, as having no mystery that is not implied in the articles on the divine omnipotence and the sanctification of man through Christ.

The Acts of Faith

786. For all adults the act of faith is necessary for salvation as a necessity of means (see 360), for the Apostle says: “Without faith it is impossible to please God.” (Heb., xi. 6.)

The truths which must be believed under necessity of means are of two kinds.

(a) One must believe with implicit faith all revealed truths which one does not know and is not bound to know. An act of implicit faith is contained in the formula: “O my God, I firmly believe all the truths the Catholic Church teaches, because Thou hast revealed them.”

(b) One must believe with explicit faith all the truths which one is bound to know. An act of explicit faith in all the truths necessary by necessity of means is contained in the Apostles’ Creed.

Other truths that must be explicitly believed on account of a necessity of precept will be discussed in 918, 920.

787. What specifically are the truths just referred to that all are bound to know as a necessary means?

(a) Theologians generally agree that it has always been necessary for adults to know and accept two basic mysteries:

  • God’s existence, as the supernatural End or happiness of man, and
  • His providence as exercised in supplying the means necessary for supernatural salvation (see 768).

Without such belief, supernatural hope and charity, at all times necessary, are impossible.

(b) A majority of theologians hold, and with greater probability it seems, that since the promulgation of the Gospel it is necessary for adults to know and accept [also] the two basic mysteries of Chrisitanity— viz.:

  • That in God, who is our beatitude, there are three persons (the Trinity), and
  • That the way to our beatitude is through Christ our Redeemer (the Incarnation).

788. Even before the Gospel, it was always necessary as a means that one believe explicitly in God as our supernatural happiness and as the provider of the means thereto. Thus, the Apostle, speaking of the ancient patriarchs, says: “He that cometh to God, must believe that He is, and is a rewarder to them that seek Him” (Heb., xi. 6). He that would come to God (i.e., be saved), must believe in God as the Author of glory and of grace. Hence, one must believe:

(a) that God exists, who is not ashamed to be called our God, and who prepares for us a better, that is, a heavenly country (Heb., xi. 6);

(b) that God is a remunerator, from whom must be expected the working out of His promises and the helps to attain the reward, as well as the meting out of justice.

In this faith is included implicitly a faith in Christ, and thus in the Old Testament a belief, at least implicit, in the Messiah to come was always necessary: “Man is not justified by the works of the law, but by the faith of Jesus Christ” (Gal., ii. 16).

789. Since the promulgation of the Gospel (see 342, 354), it is also necessary as a means that one believe explicitly in the mysteries of the Trinity and Incarnation. For he who does not accept these, does not accept the Gospel, whereas Christ says: “Go ye into the whole world, and preach the Gospel to every creature. He that believeth not shall be condemned” (Mark, xvi. 15, 16).

(a) Theoretically, this opinion seems more probable than the opposite opinion; but chiefly on account of the difficulty about negative infidels, which is discussed in dogmatic treatises on Predestination and Grace, many theologians either reject it (e.g., those who say that belief in the two great Christian mysteries is necessary only as a precept, or that implicit faith suffices), or modify it (e.g., those who say that belief in these two mysteries is not necessary as a means for justification, but only for glorification, and those who say that regularly such faith is a necessary means, but that an exception is allowed for invincible ignorance, or for the insufficient promulgation of the Gospel in many regions).

(b) Practically, this opinion [all four mysteries must be believed explicitly] is safer, and hence all theologians, even Probabilists, hold that one must act as if it were true and certain, whenever it is possible to give instruction on the Trinity and Incarnation.

790. Knowledge about the mysteries of faith is either substantial (by which one knows the essentials of a mystery) or scientific (by which one knows also its circumstances and details, and is able to give a more profound explanation of it). Scientific knowledge is required, on account of their office, in those who are bound to teach the faith, but substantial knowledge suffices for salvation.

Hence, for an adult to be saved, it suffices that he have the following kind of knowledge about the four great mysteries:

(a) There is a God who has spoken to us, promising freely that He will take us to Himself as our reward.

It is not necessary that one understand such theological concepts as the essence of deity, the definition of supernaturality, the formal and material objects of beatitude, etc.; for many persons are incapable of understanding them.

(b) This God, who will be our reward, is one, but there are three divine Persons—the Father, the Son and the Holy Ghost, really distinct and equal.

It is not necessary that one understand the distinction between nature and person, nor subtle questions about the processions and properties.

(c) God provides for us, giving us the helps we need, and also, if we serve Him, the reward He has promised.

It is not necessary that one understand the theology of providence, grace, and merit.

(d) Jesus Christ, who is God the Son, became man, suffered and died for us, thus saving us from sin and winning back for us the right to heaven.

It is not necessary that one understand scientifically that in Christ there are two natures united hypostatically in the one Person of the Word.

791. Since Baptism is fruitless without due faith in the recipient, it is not lawful as a rule to baptize those who lack substantial knowledge of the four mysteries just mentioned. (a) Outside of danger of death, it is never lawful to baptize a person, adult in mind, who is in substantial ignorance of any of these four mysteries. Such a person must first receive instruction. (b) In danger of death, when instruction cannot be given, an adult in substantial ignorance about the Trinity and the Incarnation may be baptized conditionally; for it is probable that explicit knowledge of those two mysteries is not a necessity of means (see 789; Canon 752, Sec.2).

792. Since absolution is invalid if the person absolved is incapable of receiving grace, and since acts of faith in the four chief mysteries are an essential means to justification in adults, absolution given to one who is in substantial ignorance about one of the four mysteries above mentioned is certainly or probably invalid, as the case may be. Absolution certainly invalid is never lawful, but absolution probably valid may in certain cases be regarded as lawful before administration, and as valid after administration. Hence, the following cases must be distinguished:

(a) Outside of danger of death, it is not lawful to absolve one who is in substantial ignorance about any of those four mysteries. Such a person should be sent away for further instruction, or given a brief instruction then and there, if there is time.

(b) In danger of death, when instruction cannot be given, an adult in substantial ignorance about the Trinity and Incarnation may be absolved conditionally, for the reason given in the similar case of Baptism.

(c) After the fact, absolution given to one who was in substantial ignorance of the Trinity and Incarnation, may be regarded as valid, since the opinion that explicit knowledge of these mysteries is not a necessary means, is at least probable. Hence, according to the principles of Probabilism a penitent who made confessions While ignorant of those two mysteries is not obliged to repeat his confessions, since he has probably satisfied his obligation.

793. In the following cases (which would be rare, it seems) Baptism or absolution cannot be administered, even to the dying who are unable to receive instruction:

(a) when it is certain that the dying person is substantially ignorant about the existence of God, the Author of grace and glory;

(b) when it is certain that the dying person is substantially ignorant of the Trinity and Incarnation through his own fault, and is unwilling to hear about them.

794. Practical rules for granting the Sacraments in case of doubt or urgency to those who seem to be indisposed on account of substantial ignorance are the following:

(a) In danger of death, when instruction is out of the question, if there is doubt about his ignorance, the dying person should be given the benefit of the doubt.

(b) In danger of death, and when instruction is impossible, if there is doubt about the mental ability of the dying person and his obligation to have explicit faith, he should receive the benefit of the doubt.

(c) In danger of death or other urgent necessity, when instruction is needed and possible, it should be given briefly as follows:

“Let us say the act of faith: I believe in one God, the Father, Son and Holy Ghost, who has promised to take to Himself after this life all those that love Him, and who punishes the wicked. I hope to have the happiness of being received into His companionship through the help of Jesus Christ, the Son of God, who became man and died for my salvation.”

This or a similar instruction should be given by the priest or lay person present in baptizing an adult who is about to die. When there is not immediate danger of death, a person who is baptized or absolved after short instruction on account of emergency, should be admonished of the duty of receiving fuller instruction later on.

The Commandment of Knowledge of Faith

Nos. 918 and 920 were mentioned below. I include them and some surrounding sections here – but in the context of the Simple Summary previously published, let’s note that Callan and McHugh hold that the below truths should be known “by all capable of the knowledge”. Some very elderly people may indeed not be capable of this knowledge.

In any case, such judgments are for the priest, not us who are trying to help our relatives.

913. Unlike the commandments of justice, which are summed up in the Decalogue, the commandments of faith are not given in any one place of scripture; but they may be reduced to three:

(a) one must acquire knowledge and understanding of one’s faith according to one’s state in life and duties;

(b) one must believe internally the truths of faith;

(c) one must profess externally one’s belief.


917. A person applies himself sufficiently to the understanding of the teaching of faith when he takes care that, both extensively or in quantity and intensively or in quality, his knowledge is all that is required of him.

(a) Extensively, the knowledge should be such as to include at least all those truths that have to be known, because explicit faith in them is necessary; (b) intensively, the knowledge should be more or less perfect according to the greater or less intelligence, rank or responsibility of the person.

918. The truths that have to be known by all capable of the knowledge are as follows:

(a) All must know, from the necessity of the case (necessity of means), that they have a supernatural destiny and that Christ is the Way that leads to it; for one cannot tend to a destination, if one is unaware of its existence and of the road that will bring one there. Hence, all must know the four basic truths: God our Last End, the Trinity, the Incarnation, God the Remunerator (see 787).

(b) All must know, from the will of Christ (necessity of precept), the other truths to which He wishes them expressly to assent, and the duties, general or particular, that He wishes them to fulfill (Mark, xvi. 16); that is, they must know the doctrine contained in the Creed, the commandments and ordinances of Christ concerning the Sacraments and prayer, and the special obligations of each one’s particular state or office.


920. Scientific or complete knowledge is not required of those who are not theologians, as was said about the four basic truths (see 790). It suffices for lay persons that they know in a simple way, according to their age and capacity, the substance of the truths they must believe. Thus, they should know:

(a) The Creed.—One should know about God, that He is but one and that there are three divine Persons, Father, Son and Holy Ghost; that God is the maker of the world, and that He will reward everyone according to his deeds. One should know about Christ, that He is the Son of God and God Himself; that He was miraculously born of the Blessed Virgin Mary; that He suffered and died for our salvation; that He rose from the dead and by His own power ascended into glory and will come again after the general resurrection to judge all. One should know about the Church, that it is the one true Church founded by Christ, in which are found the communication of spiritual goods and the forgiveness of sins.

(b) The Decalogue.—One should know the general meaning of the Commandments so as to be able to regulate one’s own conduct by them. It is not necessary that a child should know all the kinds of crimes and vices that are forbidden by the Commandments. In fact, it is better for such not to know much about evil. Nor is it required that a layman should know how to make correct applications of the Commandments to complicated situations that require much previous study.

(c) The Virtues.—One should know enough to be able to apply to one’s own life, for ordinary cases, what a virtuous life demands. It is not necessary that a child should know the requirements of prudence as well as an experienced person, or that a layman should be able to settle doubts of conscience as well as a priest. But each should know enough to fulfill what is required of one of his age and condition. Both old and young should know in substance the acts of faith, hope, charity and contrition; for to these all are bound. The young should know the laws of the Church that apply to them (e.g., the law of abstinence); the older people should understand the law of fasting which they are bound to observe, etc.

(d) The Sacraments.—One should know substantially the doctrine of the Sacraments that are necessary for all, namely, Baptism, Penance and the Eucharist. Since all the faithful have the duty of baptizing in case of necessity, all should know how to administer lay Baptism properly and fruitfully. When the time comes for receiving a Sacrament, the recipient should know enough to receive it validly, licitly, and devoutly, although less knowledge is required in children and in the dying who cannot be fully instructed (see Canons 752, 854, 1330, 1331, 1020).

(e) Special Duties.—One should know the essentials of one’s condition or state of life and the right way to perform its ordinary duties. Children should understand the obligations of pupils and of subjects; the married, religious and priests should know the duties of their respective states; citizens, the loyalty owed to the community; officials, judges, lawyers, physicians, teachers, etc., the responsibilities to the public which their own professions imply.

(f) The Lord’s Prayer.—The substance of this form of prayer should be known by all, namely, that God is to be glorified, and that we should ask of Him with confidence goods of soul and body and deliverance from evil. Though Christ is the only necessary Mediator (I Tim., ii. 5), it is most suitable that all should know substantially the Hail Mary, namely, that we should ask the intercession of her who is the Mother of God and our Mother (John, xix, 27).

From: McHugh & Callan – Moral Theology – A Complete Course Based on St. Thomas Aquinas and the Best Modern Authorities (and for UK readers) Two volumes. Online at Project Gutenberg and the Internet Archive here and here.


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