Faith without works of justice is not sufficient for salvation; neither is righteous living secure in itself of salvation, if it is disjoined from faith” (Homilies on Ecclesiastes 8 [ca. A.D. 335- 394]).

On Purgatory
“If a man distinguish in himself what is peculiarly human from that which is irrational, and if he be on the watch for a life of greater urbanity for himself, in this present life he will purify himself of any evil contracted, overcoming the irrational by reason. If he has inclined to the irrational pressure of the passions, using for the passions the cooperating hide of things irrational, he may afterward in a quite different manner be very much interested in what is better, when, after his departure out of the body, he gains knowledge of the difference between virtue and vice and finds that he is not able to partake of divinity until he has been purged of the filthy contagion in his soul by the purifying fire” (Sermon on the Dead [A.D. 382]).

Gregory of Nyssa
“[In] the birth by water and the Spirit, [Jesus] himself led the way in this birth, drawing down upon the water, by his own baptism, the Holy Spirit; so that in all things he became the firstborn of those who are spiritually born again, and gave the name of brethren to those who partook in a birth like to his own by water and the Spirit” (Against Eunomius 2:8 [A.D. 382]).

On the Eucharist
“The bread again is at first common bread; but when the mystery [the Eucharistic prayer] sanctifies it, it is called and actually becomes the Body of Christ. So too the mystical oil, so too the wine;…after their sanctification by the Spirit each of them has their superior operation.
Sermon on the Day of Lights [A.D. 383]).

“Just as in the time of Mary, the Mother of God,
Death, who had reigned from Adam until then,
found, when he came to her and dashed his forces
against the fruit of her virginity as against a rock,
that he was himself shattered against her,
so too is every soul that passes through this life
protected by virginity, the strength of Death
is shattered and annulled when
Death finds no place to fix its sting.”
—Virginity 14:13. (Written 370 A.D.)

On Guardian Angels
“There is an opinion having been handed down from the Fathers which says that when our nature fell into sin, God did not leave us without protection in our misery. Rather, a certain angel from among those who are allotted an incorporeal nature, was appointed by Him to assist in the life of each man;
but counter wise too, the corrupter of our nature
fights against the same by the agency of a certain
evil and malicious demon. Between these two,
in the middle is man. The goal of each of these
companion spirits is directly opposed to each other,
their goal being to prevail more effectively over the other.”
-Life of Moses 2:45-46 (Written 390 A.D.)

On Purgatory
“Those who are cut and cauterized for the sake of a cure are angry with those who are curing them, and they wince in pain at the incision. But if a cure is effected by these means, and the pain passes away, they are grateful to those who cured them.
In the same manner, when, after periods of time, the evil in our nature is expelled from it, and those lying prostrate in wickedness have been restored to their primordial condition,
all creation will give thanks in one voice, those who have been punished in purgation as well as those who had no need of purgation.”
-The Great Catechism 26 (Written in 383 A.D.)

On the Body of Christ
“Since it has been shown that it is not possible for our body to become immortal except by being in participation in incorruption through Communion with the Immortal, it is necessary to consider the possibility of that One Body, which is distributed to the myriads of the faithful throughout the world, to be whole in its appropriation to each individual, while yet remaining whole in itself.”
-The Great Catechism 37. (Written in 383 A.D.)

On the Eucharist
Rightly, then, do we believe that the bread consecrated by the word of God has been made over into the Body of God the Word. For that Body was, as to its potency, bread, but it has been consecrated by the indwelling of the Word there, who lives in the flesh.”
-The Great Catechism 37. (Written in 383 A.D.)

On the Eucharist
“As in the former case, in which the grace of the Word made holy that substance which was bread, and in a certain sense is itself bread, so in this case too, that bread which the Apostle said: ‘is consecrated by God’s word’ (1 Tim 4:5), does not become the Body of the Word by being eaten, but is immediately made into the Body, just as the Word stated, ‘This is my Body!’… He spreads Himself to every believer by means of that Flesh, the substance of which is bread and wine, blending Himself with the bodies of believers, so that by this union with the Immortal, man too may become a participant in incorruption.”
-The Great Catechism 37. (Written in 383 A.D.)

On Apostolic Tradition
“Let Eunomius first show, then, that the Church has believed in vain that the Only-Begotten Son truly exists and was not made such through adoption by a Father, who then is falsely so-called…
It suffices for the proof of our statement that we have a tradition coming down to us from the Fathers, an inheritance as it were, by succession from the Apostles through the saints who came after them.”
-Against Eunomius 3:4 (Written 380 A.D.)

On Salvation
“The Father, as the Apostle says, ‘wills that all men be saved and come to knowledge of truth,’ (1 Tim 2:4)… He does not skimp in any way the loving kindness of His will toward men, as Apollinaris would have it; He does not will that only some and not all be made alive. It is not the will of the Lord that is the reason why some are saved and some are lost; were that the case, the cause of their perdition would have to be referred to His will. That some are saved and some perish depends rather upon the deliberate choice of those who hear the word.”
-Refutation of Apollinaris 29 (Written 385 A.D.)

On the Sacrifice of the Mass
“He offered Himself for us, Victim and Sacrifice and Priest as well, and ‘Lamb of God who takes away the sins of the world’ (John 1:29). When did He do this? When He made His own Body food and His own Blood drink for His disciples; for much is clear enough to anyone, that a sheep cannot be eaten unless it is first slaughtered. This giving of His own Body to His disciples for eating clearly indicates that the sacrifice of the Lamb has now been completed.”
-Sermon on the Resurrection (Written 382 A.D.)

“It seems to me that, already, the great Moses knew about this mystery by means of the light in which God appeared to him when he saw the bush burning without being consumed (Ex 3:1). . . What was prefigured at that time in the flame of the bush was openly manifested in the mystery of the Virgin. . . As on the mountain the bush burned but was not consumed, so the Virgin gave birth to the light and was not consumed. Nor should you consider the comparison to the bush to be unfit, for it prefigures the God-bearing body of the Virgin.”
-On the Birth of Christ 46

“‘How will this happen to me, since I do not know man?’ (Lk 1:34). Mary’s own words confirm certain traditions. For if Joseph had taken her to be his wife, for the purpose of having children, why would she have wondered at the announcement of maternity, since she herself would have accepted becoming a mother according to the law of nature? . . it was necessary to guard the body consecrated to God as an untouched and Holy offering. . . How shall I become a mother without knowing man? For though I consider Joseph my husband, still I do not know man.”
-On the Birth of Christ 46

“While Gregory (Thaumaturgus) was passing a sleepless night due to these worries, someone appeared to him in human form, aged in appearance, clothed in garments denoting a sacred dignity, with a face characterized by a sense of grace and virtue.  Gregory, looking frightened, rose from his bed and asked him who he was and why he had come.  The other, in a subdued voice, soothed Gregory’s distress and told him that he had appeared by Divine Will, due to the questions that Gregory found ambiguous and confusing, to reveal to Gregory the truth of pious faith.  After hearing these words, Gregory regained his serenity and observed the man with joy and wonder.  The other held up his hand, as if to point out with his index finger, something that had appeared opposite him.  Gregory, turning his gaze, saw another figure before him.  This figure was a woman, whose noble aspect far surpassed normal human beauty.  Turning away, Gregory averted his glance, not bearing to look with his eyes.  The extraordinary vision, though it was a dark night, gave off a shining light as though a lamp had been kindled.  Although he could not bear to look upon the apparition, Gregory heard the speech of those who had appeared.  From their words, Gregory obtained the exact understanding of the doctrine of faith as well as their names.  For he heard the woman exhorting John the Evangelist to explain to Gregory the mystery of the true faith.  John, in his turn, expressed his willingness to please the  Mother of the Lord as this was the one thing closest to his heart.  When the discussion came to a close, the two disappeared from his sight.” -Life and Panegyric of Gregory the Wonderworker (213-270 A.D.). Written by Gregory of Nyssa in 380 A.D.