And here are some more of the Church Fathers expressing the apostolic faith:
Origen, ca. A.D. 185-254
We give thanks to the Creator of all, and, along with thanksgiving and prayer for the blessings we have received, we also eat the bread presented to us; and this bread becomes by prayer a sacred body, which sanctifies those who sincerely partake of it. (Against Celsus 8:33)
You are accustomed to take part in the divine mysteries, so you know how, when you have received the body of the Lord, you reverently exercise every care lest a particle of it fall, and lest anything of the consecrated gift perish... how is it that you think neglecting the word of God a lesser crime than neglecting His body? (Homilies on Exodus 13:3)
Formerly there was baptism in an obscure way . . . now, however, in full view, there is regeneration in water and in the Holy Spirit. Formerly, in an obscure way, there was manna for food; now, however, in full view, there is the true food, the flesh of the Word of God, as he himself says: "My flesh is true food, and my blood is true drink’ [John 6:56]" (Homilies on Numbers 7:2).
St. Clement of Alexandria, ca. A.D. 150-216
Calling her children about her, she [the Church] nourishes them with holy milk, that is, with the Infant Word...The Word is everything to a child: both Father and Mother, both Instructor and Nurse. "Eat My flesh," He says, "and drink My blood." The Lord supplies us with these intimate nutriments. He delivers over His flesh amd pours out His blood; and nothing is lacking for the growth of His children. O incredible mystery! (Instructor of Children 1:6:42,1,3)
St. Cyprian of Carthage, ca A.D. 200-258
He Himself warns us, saying, "Unless you eat the flesh of the Son of Man and drink His blood you shall not have life in you." Therefore do we ask that our Bread, which is Christ, be given to us daily, so that we who abide and live in Christ may not withdraw from His sanctification and from His Body. (The Lord's Prayer 18)
St. Aprahat, ca A.D. 280-345
After having spoken thus ["This is My body, This is My blood"], the Lord rose up from the place where He had made the Passover and had given His Body as food and His Blood as drink, and He went with His disciples to the place where He was to be arrested. But He ate of His own Body and drank of His own Blood, while He was pondering on the dead. With His own hands the Lord presented His own Body to be eaten, and before He was crucified He gave His blood as drink... (Treatises 12:6)
St. Ephraim the Syrian, ca. A.D. 306-373
Our Lord Jesus took in His hands what in the beginning was only bread; and He blessed it, and signed it, and made it holy in the name of the Father and in the name of the Spirit; and He broke it and in His gracious kindness He distributed it to all His disciples one by one. He called the bread His living Body, and did Himself fill it with Himself and the Spirit. And extending His hand, He gave them the Bread which His right hand had made holy: "Take, all of you eat of this, which My word has made holy. Do not now regard as bread that which I have given you; but take, eat this Bread, and do not scatter the crumbs; for what I have called My Body, that it is indeed. One particle from its crumbs is able to sanctify thousands and thousands, and is sufficient to afford life to those who eat of it. Take, eat, entertaining no doubt of faith, because this is My Body, and whoever eats it in belief eats in it Fire and Spirit. But if any doubter eat of it, for him it will be only bread. And whoever eats in belief the Bread made holy in My name, if he be pure, he will be preserved in his purity; and if he be a sinner, he will be forgiven." But if anyone despise it or reject it or treat it with ignominy, it may be taken as a certainty that he treats with ignominy the Son, who called it and actually made it to be His Body.
After the disciples had eaten the new and holy Bread, and when they understood by faith that they had eaten of Christ's body, Christ went on to explain and to give them the whole Sacrament. He took and mixed a cup of wine. Then He blessed it, and signed it, and made it holy, declaring that it was His own Blood, which was about to be poured out...Christ commanded them to drink, and He explained to them that the cup which they were drinking was His own Blood: "This is truly My Blood, which is shed for all of you. Take, all of you, drink of this, because it is a new covenant in My Blood. As you have seen Me do, do you also in My memory. Whenever you are gathered together in My name in Churches everywhere, do what I have done, in memory of Me. Eat My Body, and drink My Blood, a covenant new and old." (Homilies 4:4; 4:6)
St. Athanasius, ca. A.D. 295-373
You shall see the Levites bringing loaves and a cup of wine, and placing them on the table. So long as the prayers of supplication and entreaties have not been made, there is only bread and wine. But after the great and wonderful prayers have been completed, then the bread is become the Body, and the wine the Blood, of our Lord Jesus Christ... Let us approach the celebration of the mysteries. This bread and this wine, so long as the prayers and supplications have not taken place, remain simply what they are. But after the great prayers and holy supplications have been sent forth, the Word comes down into the bread and wine -- and thus is His Body confected. (Sermon to the Newly Baptized, from Eutyches)
St. Cyril of Jerusalem, ca. A.D. 350
For just as the bread and the wine of the Eucharist before the holy invocation of the adorable Trinity were simple bread and wine, but the invocation having been made, the bread becomes the Body of Christ and the wine the Blood of Christ... (Catechetical Lectures 19 [Mystagogic 1], 7)
This one teaching of the blessed Paul is enough to give you complete certainty about the Divine Mysteries, by your having been deemed worthy of which, you have become united in body and blood with Christ. For Paul proclaimed clearly that: "On the night in which He was betrayed, our Lord Jesus Christ, taking bread and giving thanks, broke it and gave it to His disciples, saying: 'Take, eat, This is My Body.' And taking the cup and giving thanks, He said, 'Take, drink, This is My Blood.'" He Himself, therefore, having declared and said of the Bread, "This is My Body," who will dare any longer to doubt? And when He Himself has affirmed and said, "This is My Blood," who can ever hesitate and say it is not His Blood? (22 [Mystagogic 4], 1)
Do not, therefore, regard the Bread and the Wine as simply that; for they are, according to the Master's declaration, the Body and Blood of Christ. Even though the senses suggest to you the other, let faith make you firm. Do not judge in this matter by taste, but -- be fully assured by the faith, not doubting that you have been deemed worthy of the Body and Blood of Christ. (22 [Mystagogic 4], 6)
Then, having sanctified ourselves by these spiritual songs, we call upon the benevolent God to send out the Holy Spirit upon the gifts which have been laid out: that He may make the bread the Body of Christ, and the wine the Blood of Christ; for whatsoever the Holy Spirit touches, that is sanctified and changed. (23 [Mystagogic 5], 7)
St. Hilary of Poitiers, ca. A.D. 315 - 368
When we speak of the reality of Christ's nature being in us, we would be speaking foolishly and impiously -- had we not learned it from Him. For He Himself says: "My Flesh is truly Food, and My Blood is truly Drink. He that eats My Flesh and drinks My Blood will remain in Me and I in Him." As to the reality of His Flesh and Blood, there is no room left for doubt, because now, both by the declaration of the Lord Himself and by our own faith, it is truly Flesh and it is truly Blood. And These Elements bring it about, when taken and consumed, that we are in Christ and Christ is in us. Is this not true? Let those who deny that Jesus Christ is true God be free to find these things untrue. But He Himself is in us through the flesh and we are in Him, while that which we are with Him is in God. (The Trinity 8:14)
St. Gregory of Nyssa, ca. A.D. 335 - 394
This Body, by the indwelling of God the Word, has been made over to divine dignity. 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 lodging there of the Word, who pitched His tent in the flesh. From the same cause, therefore, by which the bread that was made over into that Body is made to change into divine strength, a similar result now takes place. As in the former case, in which the grace of the Word made holy that body the substance of which is from bread, and in a certain manner is itself bread, so in this case too, the bread, as the Apostle says, "is consecrated by God's word and by prayer"; not through its being eaten does it advance to become the Body of the Word, but it is made over immediately into the Body by means of the word, just as was stated by the Word, "This is My Body!" ...In the plan of His grace He spreads Himself to every believer by means of that Flesh, the substance of which is from wine and bread, blending Himself with the bodies of believers, so that by this union with the Immortal, man, too, may become a participant in incorruption.
St. Augustine
Christ was carried in his own hands when, referring to his own body, he said, "This is my body" [Matt. 26:26]. For he carried that body in his hands. (Explanations of the Psalms 33:1:10).
That bread which you see on the altar, having been sanctified by the word of God, is the body of Christ. That chalice, or rather, what is in that chalice, having been sanctified by the word of God, is the blood of Christ. (Sermons 227).
What you see is the bread and the chalice; that is what your own eyes report to you. But what your faith obliges you to accept is that the bread is the body of Christ and the chalice is the blood of Christ. This has been said very briefly, which may perhaps be sufficient for faith; yet faith does not desire instruction. (Sermons 272)..