The Early Church Fathers on various topics: This was a 3700 hour project which included going through 22896 pages of the 38 volume set called Ante Nicene, Nicene, Post Nicene Fathers. I compiled 255 pages of quotes showing that the Early Church was always and completely Catholic. All of these quotes can be verified and found from the source which is free online.
Clement of Alexandria Stromata Book 2 Ch 8 (150-215 ad)
He, then, who from among the Gentiles and from that old life has betaken himself to faith, has obtained forgiveness of sins once. But he who has sinned after this, on his repentance, though he obtain pardon, ought to fear, as one no longer washed to the forgiveness of sins.
Clement of Alexandria Stromata book 4 ch 23 (150-215 ad)
Thus we say that Adam was perfect, as far as respects his formation; for none of the distinctive characteristics of the idea and form of man were wanting to him; but in the act of coming into being he received perfection. And he was justified by obedience; this was reaching manhood, as far as depended on him. And the cause lay in his choosing, and especially in his choosing what was forbidden.
Hippolytus Refutation of All Heresies book 5 ch 2 (170-236 ad)
And again, it is said, the Saviour has declared, "Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven, but he that doeth the will of my Father which is in heaven." And it is necessary that they who perform this (will), not hear it merely, should enter into the kingdom of heaven.
Origen de Principiis book 3 ch 1.18 (185- 254 ad)
Having now repelled these objections by the answer which we have given, let us hasten on to the discussion of the subject itself, in which it is said, "It is not of him that willeth, nor of him that runneth, but of God that showeth mercy." In the book of Psalms--in the Songs of Degrees, which are ascribed to Solomon--the following statement occurs: "Except the Lord build the house, they labour in vain that build it; except the Lord keep the city, the watchman waketh but in vain." By which words he does not indeed indicate that we should cease from building or watching over the safe keeping of that city which is within us; but what he points out is this, that whatever is built without God, and whatever is guarded without him, is built in vain, and guarded to no purpose. For in all things that are well built and well protected, the Lord is held to be the cause either of the building or of its protection. As if, e.g., we were to behold some magnificent structure and mass of splendid building reared with beauteous architectural skill, would we not justly and deservedly say that such was built not by human power, but by divine help and might? And yet from such a statement it will not be meant that the labour and industry of human effort were inactive, and effected nothing at all. Or again, if we were to see some city surrounded by a severe blockade of the enemy, in which threatening engines were brought against the walls, and the place hard pressed by a vallum, and weapons, and fire, and all the instruments of war, by which destruction is prepared, would we not rightly and deservedly say, if the enemy were repelled and put to flight, that the deliverance had been wrought for the liberated city by God? And yet we would not mean, by so speaking, that either the vigilance of the sentinels, or the alertness of the young men, or the protection of the guards, had been wanting. And the apostle also must be understood in a similar manner, because the human will alone is not sufficient to obtain salvation; nor is any mortal running able to win the heavenly (rewards), and to obtain the prize of our high calling of God in Christ Jesus, unless this very good will of ours, and ready purpose, and whatever that diligence within us may be, be aided or furnished with divine help. And therefore most logically did the apostle say, that "it is not of him that willeth, nor of him that runneth, but of God that showeth mercy;" in the same manner as if we were to say of agriculture what is actually written: "I planted, Apollos watered; but God gave the increase. So then neither is he that planteth anything, neither he that watereth; but God that giveth the increase." As, therefore, when a field has brought good and rich crops to perfect maturity, no one would piously and logically assert that the husbandman had made those fruits, but would acknowledge that they had been produced by God; so also is our own perfection brought about, not indeed by our remaining inactive and idle, (but by some activity on our part): and yet the consummation of it will not be ascribed to us, but to God, who is the first and chief cause of the work. So, when a ship has overcome the dangers of the sea, although the result be accomplished by great labour on the part of the sailors, and by the aid of all the art of navigation, and by the zeal and carefulness of the pilot, and by the favouring influence of the breezes, and the careful observation of the signs of the stars, no one in his sound senses would ascribe the safety of the vessel, when, after being tossed by the waves, and wearied by the billows, it has at last reached the harbour in safety, to anything else than to the mercy of God. Not even the sailors or pilot venture to say, "I have saved the ship," but they refer all to the mercy of God; not that they feel that they have contributed no skill or labour to save the ship, but because they know that while they contributed the labour, the safety of the vessel was ensured by God. So also in the race of our life we ourselves must expend labour, and bring diligence and zeal to bear; but it is from God that salvation is to be hoped for as the fruit of our labour. Otherwise, if God demand none of our labour, His commandments will appear to be superfluous. (not by faith alone)
Cyprian of Carthage Treatise 3 par 35 (200-270 ad)
be earnest in righteous works, whereby sins may be purged; frequently apply yourself to almsgiving, whereby souls are freed from death
Cyril of Jerusalem Catechetical Lecture 8 par 6 (315-386 ad)
A man may even be justified by money: I was hungry, and ye gave Me meat: that certainly was from money. I was naked, and ye clothed Me: that certainly was by money. And wouldest thou learn that money may become a door of the kingdom of heaven? Sell, saith He, that thou hast, and give to the poor, and thou shalt have treasure in heaven.
Cyril of Jerusalem Catechetical Lecture 15 par 26 (315-386 ad)
How then, some one will say, are we to escape the fire? And how to enter into the kingdom? I was an hungered, He says, and ye gave Me meat. Learn hence the way; there is here no need of allegory, but to fulfil what is said. I was an hungered, and ye gave Me meat; I was thirsty, and ye gave Me drink; I was a stranger, and ye took Me in; naked, and ye clothed Me; I was sick, and ye visited Me; I was in prison, and ye came unto Me. These things if thou do, thou shall reign together with Him; but if thou do them not, thou shalt be condemned. At once then begin to do these works, and abide in the faith; lest, like the foolish virgins, tarrying to buy oil, thou be shut out. Be not confident because thou merely possessest the lamp, but constantly keep it burning
Gregory Nazianzen Oration 40 par 19 (325-389 ad)
Rahab the harlot was justified by one thing alone, her hospitality,(a) though she receives no praise for the rest of her conduct; and the Publican was exalted by one thing, his humility,(b) though he received no testimony for anything else; so that you may learn not easily to despair concerning yourself.
Basil Letter 295 (329-379 ad)
Faith and works must be joined: so shall the man of God be perfect, and his life not halt through any imperfection.
For the faith which saves us, as saith the Apostle, is that which worketh by love.
Ambrose of Milan On the Christian Faith book 2 par 11 (340-397 ad)
For those are good things, whereof the texture of the priestly robe was the token, that is to say, either the Law, or the Church, which latter hath made two garments for her spouse, as it is written'--the one of action, the other of spirit, weaving together the threads of faith and works.
Jerome Letter 130 par 11 (347-420 ad)
The same may be said of sanctification and of that chastity without which no man shall see the Lord. Each of these is a step on the upward way, yet none of them by itself will avail to win the virgin's crown. The gospel teaches us this in the parable of the wise and foolish virgins; the former of whom enter into the bridechamber of the bridegroom, while the latter are shut out from it because not having the oil of good works they allow their lamps to fail.
John Chrysostom Homily 4 on Ephesians ch 2:8 (347-407 ad)
Was faith then, you will say, enough to save us? No; but God, saith he, hath required this, lest He should save us, barren and without work at all. His expression is, that faith saveth, but it is because God so willeth, that faith saveth. Since, how, tell me, doth faith save, without works? This itself is the gift of God.
John Chrysostom Homily 1 on Ephesians ch 1:4 (347-407 ad)
But wherefore hath He chosen us? "That we should be holy and without a blemish before Him." That you may not then, when you hear that "He hath chosen us," imagine that faith alone is sufficient, he proceeds to add life and conduct. To this end, saith he, hath He chosen us, and on this condition, "that we should be holy and without blemish."
John Chrysostom Homily 4 on Philippians (347-407 ad)
And again, "And let our people also learn to maintain good works." (Tit. iii. 14.) And again, "These things are good and profitable unto men." (Tit. iii. 8.) Listen to a certain other one who saith, "Alms do deliver from death" (Tob. xii. 9)
John Chrysostom Homily 46 on John’s gospel (347-407 ad)
How long shall we neglect our own salvation? Let us bear in mind of what things Christ has deemed us worthy, let us give thanks, let us glorify Him, not by our faith alone, but also by our very works, that we may obtain the good things that are to come, through the grace and lovingkindness of our Lord Jesus Christ, by whom and with whom, to the Father and the Holy Ghost be glory, now and ever and world without end
John Chrysostom Homily 31 on John’s gospel (347-407 ad)
Since though he has said here, "He that believeth on the Son hath eternal life," and in the same place something even stronger, (for he weaves his discourse not of blessings only, but of their contraries also, speaking thus: "He that believeth not the Son shall not see life, but the wrath of God abideth on him";) yet not even from this do we assert that faith alone is sufficient to salvation.
John Chrysostom Homily 3 on Second Thessalonians (347-407 ad)
Since he also who was clothed in filthy garments, was called, but did not abide in his calling, but for this reason was the more rejected. "Of the calling," namely that to the bride-chamber. Since the five virgins also were called. "Arise" it says, "the bridegroom cometh." (From Matt. xxv. 6.) And they prepared themselves, but did not enter in. But he speaks of that other calling. Showing therefore what calling he is speaking of, he has added, "And fulfill every desire of goodness and every work of faith, with power." This is the calling, he says, that we seek. See how gently he takes them down. For that they may not be rendered vain by the excess of commendation, as if they had done great deeds, and may not become slothful, he shows that something still is wanting to them, so long as they are in this life.
John Chrysostom Homily 39 on John’s gospel (347-407 ad)
For because He had said above, "He that heareth My words and believeth on Him that sent Me," "is not judged," lest any one should imagine that this alone is sufficient for salvation, He addeth also the result of man's life, declaring that "they which have done good shall come forth unto the resurrection of life, and they that have done evil unto the resurrection of judgment."
John Chrysostom Homily 6 on John’s gospel (347-407 ad)
For though we have all faith and all knowledge of the Scriptures, yet if we be naked and destitute of the protection derived from (holy) living, there is nothing to hinder us from being hurried into the fire of hell, and burning for ever in the unquenchable flame. For as they who have done good shall rise to life everlasting, so they who have dared the contrary shall rise to everlasting punishment, which never has an end.
John Chrysostom Homily 10 on John’s gospel (347-407 ad)
For even in these mystical blessings, it is, on the one hand, God's part, to give the grace, on the other, man's to supply faith; and in after time there needs for what remains much earnestness. In order to preserve our purity, it is not sufficient for us merely to have been baptized and to have believed, but we must if we will continually enjoy this brightness, display a life worthy of it.
John Chrysostom Homily 10 on John’s gospel (347-407 ad)
For there is no small fear, lest, having sometime defiled that beautiful robe by our after sloth and transgressions, we be cast out from the inner room and bridal chamber, like the five foolish virgins, or him who had not on a wedding garment. (Matt. xxv.; xxii.) He too was one of the guests, for he had been invited; but because, after the invitation and so great an honor, he behaved with insolence towards Him who had invited him, hear what punishment he suffers, how pitiable, fit subject for many tears. For when he comes to partake of that splendid table, not only is he forbidden the least, but bound hand and foot alike, is carried into outer darkness, to undergo eternal and endless wailing and gnashing of teeth.
Augustine of Hippo Enchiridion ch 67 [354-430 AD]
For Holy Scripture, when consulted, gives a very different answer. I have written a book on this subject, entitled Of Faith and Works, in which, to the best of my ability, God assisting me, I have shown from Scripture, that the faith which saves us is that which the Apostle Paul clearly enough describes when he says: "For in Jesus Christ neither circumcision availeth anything, nor uncircumcision, but faith which worketh by love." But if it worketh evil, and not good, then without doubt, as the Apostle James says, "it is dead, being alone." The same apostle says again, "What doth it profit, my brethren, though a man say he hath faith, and have not works? Can faith save him?" And further, if a wicked man shall be saved by fire on account of his faith alone, and if this is what the blessed Apostle Paul means when he says, without works can save a man, and what his fellow-apostle James says must be false. And that must be false which Paul himself says in another place: "Be not deceived: neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor abusers of themselves with mankind, nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners; shall inherit the kingdom of God." For if those who persevere in these wicked courses shall nevertheless be saved on account of their faith in Christ, how can it be true that they shall not inherit the kingdom of God
Augustine Tractate 25 on the gospel of John (354-430 ad)
"Jesus answered and said unto them, This is the work of God, that ye believe on Him whom He has sent." This is then to eat the meat, not that which perisheth, but that which endureth unto eternal life. To what purpose dost thou make ready teeth and stomach? Believe, and thou hast eaten already. Faith is indeed distinguished from works, even as the apostle says, "that a man is justified by faith without the works of the law:" there are works which appear good, without faith in Christ; but they are not good, because they are not referred to that end in which works are good;
Augustine Exposition on Psalm 78 par 7 (354-430 ad)
For when the spirit of man doth work together with the Spirit of God working, then there is fulfilled that which God hath commanded: and this doth not come to pass, except by believing in Him that doth justify an ungodly man. Which faith the generation crooked and embittering had not: and therefore concerning the same hath been said, "The spirit thereof hath not been trusted with God." For this hath been said much more exactly to point out the grace of God, which doth work not only remission of sins, but also doth make the spirit of man to work together therewith in the work of good deeds, as though he were saying, his spirit hath not believed in God. For to have the spirit trusted with God, is, not to believe that his spirit is able to do righteousness without God, but with God. For this is to believe in God: which is surely more than to believe God. For ofttimes we must believe even a man, though in him we must not believe. To believe in God therefore is this, in believing to cleave unto God who worketh good works, in order to work with Him well
Leo the Great Sermon 33 (395-461 ad)
In which regard, dearly-beloved, ye ought all to help one another in turn, that in the kingdom of God, which is reached by right faith and good works, ye may shine as the sons of light: through our Lord Jesus Christ, Who with God the Father and the Holy Spirit lives and reigns for ever and ever. Amen.