Justin Martyr (AD 110-165) “And this food is called among us Eucharistia (The Eucharist) , of which no one is allowed to partake but the man who believes that the things which we teach are true, and who has been washed with the washing that is for the remission of sins, unto regeneration, and who is so living as Christ enjoined. For not as common bread and common drink do we receive these; but in like manner as Jesus Christ our Saviour, having been made flesh by the Word of God, had both flesh and blood for our salvation, so likewise we have been taught that the food which is blessed by the prayer of His word, and from which our blood and flesh by transmutation are nourished, is the flesh and blood of that Jesus who was made flesh. For the Apostles, in the memoirs composed by them, which are called Gospels have delivered unto us which was enjoined upon them…” (First Apology, Ch LXVI)
Irenaeus (AD 120-202) “For as the bread, which is produced from the earth, when it receives the invocation of God, is no longer common bread, but Eucharist, consisting of two realities, earthly and heavenly; so also our bodies, when they receive the Eucharist, are no longer corruptable, having the hope of the resurrection to eternity” (Against Heresies, Book 4, Ch XVIII)
Tertullian (AD 145-220) “Our flesh eats the body and blood of Christ so that our soul is filled with God. Therefore what He joins together in His work cannot be separated in His reward”
Augustine (AD 354-430) “Receive in this bread that which was hanged on the cross; receive in this cup that which was poured from Christ’s side. For he will gain death, not life, who thinks Christ is a liar” (Ad neophytos)
“We however, take into our believing hearts and mouths the Mediator between God and man, the man Jesus Christ with His flesh given us to eat and His blood given us to drink” (Contra aversarium legis et prophetarum, Bk 2, Ch 9)
Chrysostom (AD 347-407) “The table of the Lord takes the place of the manger, for in it lies the body of the Lord, not indeed wrapped in swaddling clothes but clothed with the Holy Spirit” (Oratio de philogonio)
(Regarding 1 Cor.10:16)…“That which is in the cup is that which flowed from His side, and that is what we participate in” “When we hold that cup in our hands we glorify God and stand amazed at the ineffable gift, namely, that He shed this very thing, and not only shed it but also distributes it to us all” (Homily 24 on First Corinthians)
Martin Luther (AD 1483-1546) “What is the Sacrament of the altar? It is the true body and blood of our Lord Jesus Christ under the bread and wine, for Christains to eat and drink, instituted by Christ Himself” (Small Catechism)
“Apply in the Sacrament what is true in the person of Christ. In order that the Godhead dwell in Him, it is not necessary that the human nature be transubstantiated and the Godhead be contained under the accidents, but since both natures are present in their entirety, it is truly said: This man is God, and, This God is man. Even though philosophy does not grasp this, faith does grasp it; and the authority of the Word of God is greater than the grasp of our intellect. Just so in the Sacrament. In order that the real body and the real blood may be in the Sacrament, it is not necessary that the bread and wine be transubstantiated and Christ be contained under their accidents; but both remain there together, and it is truly said: This bread is My body; This wine is My blood.” (Luther’s Works, St Louis ed. 19, 29f)