The early Church Fathers were unanimous in teaching the reality of venial and mortal sins and that not all sins are equal as they recognized not only the savific power of baptism but also the damning power of certain serious sins. Below are the testimonies of the early witnesses of authentic Christian faith:
The Twelve Apostles
“Watch for your life’s sake. Let not your lamps be quenched, nor your loins unloosed; but be ready, for you know not the hour in which our Lord comes. But you shall assemble together often, seeking the things which are befitting to your souls: for the whole time of your faith will not profit you, if you be not made complete in the last time” (Didache 16 [A.D. 70]).
Hermas, brother of Pope Pius I
“And as many of them . . . as have repented, shall have their dwelling in the tower [i.e., the Church]. And those of them who have been slower in repenting shall dwell within the walls. And as many as do not repent at all, but abide in their deeds, shall utterly perish. . . . But if any one relapse into strife, he will be cast out of the tower, and will lose his life. Life is the possession of all who keep the commandments of the Lord” (The Shepherd 3:8:7 [A.D. 80]).
Ignatius, bishop of Antioch
“And pray without ceasing in behalf of other men; for there is hope of the repentance, that they may attain to God. For cannot he that falls arise again, and he may attain to God?” (Letter to the Ephesians 10 [A.D. 110]).
Justin Martyr, apologist
“[E]ternal fire was prepared for him who voluntarily departed from God and for all who, without repentance, persevere in apostasy” (fragment in Irenaeus, Against Heresies 5:26 [A.D. 156]).
“But observe here that every great sin is a loss of the talents of the master of the house, and such sins are committed by fornicators, adulterers, abusers of themselves with men, effeminate, idolaters, murderers.” (Commentary on Matthew, book XIV, ch. 10 [AD 185-254])
Irenaeus, bishop of Lugdunum in Gaul
“[T]o Christ Jesus, our Lord, and God, and Savior, and King, according to the will of the invisible Father, ‘every knee should bow, of things in heaven, and things on earth, and things under the earth, and that every tongue should confess’ [Philippians 2:10–11] to him, and that he should execute just judgment towards all. . . . [T]he ungodly and unrighteous and wicked and profane among men [shall go] into everlasting fire; but [he] may, in the exercise of his grace, confer immortality on the righteous, and holy, and those who have kept his commandments, and have persevered in his love, some from the beginning [of their Christian course], and others from [the date of] their penance, and may surround them with everlasting glory” (Against Heresies 1:10:1 [A.D. 189]).
“[Regarding confession, some] flee from this work as being an exposure of themselves, or they put it off from day to day. I presume they are more mindful of modesty than of salvation, like those who contract a disease in the more shameful parts of the body and shun making themselves known to the physicians; and thus they perish along with their own bashfulness” (Repentance 10:1 [A.D. 203]).
“Discipline governs a man, power sets a seal upon him; apart from the fact that power is the Spirit, but the Spirit is God. What, moreover, used [the Spirit] to teach? That there must be no communicating with the works of darkness. Observe what he bids. Who, moreover, was able to forgive sins? This is his alone prerogative: for ‘who remits sins but God alone?’ and, of course, [who but he can remit] mortal sins, such as have been committed against himself and against his temple?” (Modesty 21 [A.D. 220]).
Cyprian, bishop of Carthage
“Of how much greater faith and salutary fear are they who . . . confess their sins to the priests of God in a straightforward manner and in sorrow, making an open declaration of conscience . . . I beseech you, brethren, let everyone who has sinned confess his sin while he is still in this world, while his confession is still admissible, while the satisfaction and remission made through the priests are still pleasing before the Lord” (The Lapsed 28 [A.D. 251]).
“By the sacrament of baptism, the filth of the old man is washed away by them, that they pardon the former mortal sins, that they make sons of God by heavenly regeneration, and renew to eternal life by the sanctification of the divine layer.” (Epistle 74.17 [AD 200-270])
Basil the Great, bishop of Caesarea Mazaca in Cappadocia, Asia Minor
“The clergyman who is deposed for mortal sin shall not be excommunicated” (Canonical Letter, canon 32 [A.D. 374]).
Pacian, bishop of Barcelona in Catalonia
“Stinginess is remedied by generosity, insult by apology, perversity by honesty, and for whatever else, amends can be made by practice of the opposite. But what can he do who is contemptuous of God? What shall the murderer do? What remedy shall the fornicator find? . . . These are capital sins, brethren, these are mortal. Someone may say: ‘Are we then about to perish? . . . Are we to die in our sins?’ . . . I appeal first to you brethren who refuse penance for your acknowledged crimes. You, I say, who are timid after your impudence, who are bashful after your sins, who are not ashamed to sin but now are ashamed to confess” (Sermon Exhorting to Penance 4 [A.D. 385]).
Jerome, presbyter of Rome
“There are venial sins and there are mortal sins. It is one thing to owe ten thousand talents, another to owe but a farthing. We shall have to give an accounting for an idle word no less than for adultery. But to be made to blush and to be tortured are not the same thing; not the same thing to grow red in the face and to be in agony for a long time . . . If we entreat for lesser sins we are granted pardon, but for greater sins, it is difficult to obtain our request. There is a great difference between one sin and another” (Against Jovinian 2:30 [A.D. 393]).
John Chrysostom, archbishop of Constantinople
“For not for all sins are there the same punishments, but many and diverse, according to the times, according to the persons, according to their rank, according to their understanding, according to other things besides. And that what I say may be more clear, let one sin be set forth, fornication; and mark how many different punishments I find not from myself, but from the divine Scriptures. Did any one commit fornication before the law, he is differently punished; and this Paul showeth, ‘For as many as have sinned without law, shall also perish without law.’ Did any one commit fornication after the law? He shall suffer more grievous things. ‘For as many as have sinned in the law shall be judged by the law.’ Did any one commit fornication being a priest, he receives from his dignity a very great addition to his punishment.” (Homily 75 on Matthews Gospel [AD 347-407])
“Well then, shall the whoremonger, and the adulterer, and the man who hath done evils unnumbered, enjoy the same advantages with the man who has exhibited soberness and holiness, and Paul is to stand with Nero, or rather even the devil with Paul? For if there be no hell and yet there will be a Resurrection of all, then the wicked will attain to the same good things!” (Homily 25 on Romans [AD 347-407])
John Cassian, theologian
“And in the same way we hold that no lie can be employed by any one, I will not say rightly, but not even venially.” (Conference XVII ch. 18 [AD 360-435])
Augustine, bishop of Hippo
“[N]othing could have been devised more likely to instruct and benefit the pious reader of sacred Scripture than that, besides describing praiseworthy characters as examples, and blameworthy characters as warnings, it should also narrate cases where good men have gone back and fallen into evil, whether they are restored to the right path or continue irreclaimable; and also where bad men have changed, and have attained to goodness, whether they persevere in it or relapse into evil; in order that the righteous may be not lifted up in the pride of security, nor the wicked hardened in despair of cure” (Against Faustus 22:96 [A.D. 400]).
“[A]lthough they were living well, [they] have not persevered therein; because they have of their own will been changed from a good to an evil life, and on that account are worthy of rebuke; and if rebuke should be of no avail to them, and they should persevere in their ruined life until death, they are also worthy of divine condemnation forever. Neither shall they excuse themselves, saying—as now they say, ‘Why are we rebuked?’—so then, ‘Why are we condemned, since indeed, that we might return from good to evil, we did not receive that perseverance by which we should abide in good?’ They shall by no means deliver themselves by this excuse from righteous condemnation. . . . since it may be said, ‘O man, in that which you have heard and kept, in that you might persevere if you want’” (Admonition and Grace 11 [A.D. 426]).
“But those who do not belong to the number of the predestined . . . are judged most justly according to their deserts. For either they lie under sin which they contracted originally by their generation and go forth [from this life] with that hereditary debt which was not forgiven by regeneration [baptism], or [if it was forgiven by regeneration] they have added others besides through free choice: choice, I say, free; but not freed. . . . Or they receive God’s grace, but they are temporal and do not persevere; they abandon it and are abandoned. For by free will, since they have not received the gift of perseverance, they are sent away in God’s just and hidden judgment” (ibid., 13).
“[O]f two pious men, why to the one should be given perseverance unto the end, and to the other it should not be given, God’s judgments are even more unsearchable. . . . had not both been called and followed him that called them? And had not both become, from wicked men, justified men, and both been renewed by the laver of regeneration?” (The Gift of Perseverance 9:21 [A.D. 428]).
Caesarius, bishop of Arles
“Although the apostle [Paul] has mentioned many grievous sins, we, nevertheless, lest we seem to promote despair, will state briefly what they are. Sacrilege, murder, adultery, false witness, theft, robbery, pride, envy, avarice, and, if it is of long standing, anger, drunkenness, if it is persistent, and slander are reckoned in their number. Or if anyone knows that these sins dominate him, if he does not do penance worthily and for a long time, if such time is given him . . . he cannot be purged in that transitory fire of which the apostle spoke [1 Cor. 3:11–15], but the eternal flames will torture him without any remedy. But since the lesser sins are, of course, known to all, and it would take too long to mention them all, it will be necessary for us only to name some of them . . . There is no doubt that these and similar deeds belong to the lesser sins which, as I said before, can scarcely be counted, and from which not only all Christian people, but even all the saints could not and cannot always be free. We do not, of course, believe that the soul is killed by these sins, but still they make it ugly by covering it as if with some kind of pustules and, as it were, with horrible scabs” (Sermons 179:2 [A.D. 522]).
WHO will then say that venial and mortal sins are mere inventions of the Holy Catholic Church?