“And as they were eating, he took bread, and blessed, and broke it, and gave it to them, and said, "Take; this is my body." And he took a cup, and when he had given thanks he gave it to them, and they all drank of it. And he said to them, "This is my blood of the covenant, which is poured out for many. Truly, I say to you, I shall not drink again of the fruit of the vine until that day when I drink it new in the kingdom of God."”
Short answer
The Church teaches that by the consecration the whole substance of the bread and wine is changed into the Body and Blood of Christ, while the appearances of bread and wine remain. Scripture keeps the names "bread" and "cup" for what is seen, and the same passages call what is received the body and blood of the Lord. The word transubstantiation came into use in the Middle Ages. The belief that the bread and wine are changed is found in the Fathers many centuries before the word.
Drafted from primary sources. Every quotation is checked against the page it links to. The project's objection table cites Mk. 15:22-25, which is the crucifixion. This is almost certainly a slip for Mark 14:22-25, the Last Supper, and the timeline quotes that passage. The verses field is kept as the table gives it.
Where this teaching appears on the Offshoots timelines: 1079, The change of the bread and wine denied: Berengar of Tours.
15 quotations in date order
“And he took a cup, and when he had given thanks he said, "Take this, and divide it among yourselves; for I tell you that from now on I shall not drink of the fruit of the vine until the kingdom of God comes."”
“For I received from the Lord what I also delivered to you, that the Lord Jesus on the night when he was betrayed took bread, and when he had given thanks, he broke it, and said, "This is my body which is for you. Do this in remembrance of me." … For as often as you eat this bread and drink the cup, you proclaim the Lord's death until he comes.”
“When, therefore, the mingled cup and the manufactured bread receives the Word of God, and the Eucharist of the blood and the body of Christ is made, from which things the substance of our flesh is increased and supported, how can they affirm that the flesh is incapable of receiving the gift of God, which is life eternal, which [flesh] is nourished from the body and blood of the Lord, and is a member of Him?”
“Having learned these things, and been fully assured that the seeming bread is not bread, though sensible to taste, but the Body of Christ; and that the seeming wine is not wine, though the taste will have it so, but the Blood of Christ…”
“Let us prove that this is not what nature made, but what the blessing consecrated, and the power of blessing is greater than that of nature, because by blessing nature itself is changed. … The Lord Jesus Himself proclaims: This is My Body. … Before the blessing of the heavenly words another nature is spoken of, after the consecration the Body is signified.”
“For His word cannot deceive, but our senses are easily beguiled. That has never failed, but this in most things goes wrong. Since then the word says, This is my body, let us both be persuaded and believe, and look at it with the eyes of the mind.”
“And now you ask, how the bread became Christ's body and the wine and water Christ's blood. And I say unto you, The Holy Spirit is present and does those things which surpass reason and thought.”
“I believe in my heart and openly profess that the bread and wine that are placed on the altar are, through the mystery of the sacred prayer and the words of the Redeemer, substantially changed into the true and proper and lifegiving flesh and blood of Jesus Christ our Lord…”
“His body and blood are truly contained in the sacrament of the altar under the forms of bread and wine, the bread and wine having been changed in substance, by God's power, into his body and blood, so that in order to achieve this mystery of unity we receive from God what he received from us.”
“And this is done by Divine power in this sacrament; for the whole substance of the bread is changed into the whole substance of Christ's body, and the whole substance of the wine into the whole substance of Christ's blood. Hence this is not a formal, but a substantial conversion; nor is it a kind of natural movement: but, with a name of its own, it can be called "transubstantiation."”
“After the consecration bread can be said to be in this sacrament in two ways. First, as to the species, which retain the name of the previous substance … Secondly, Christ's very body can be called bread, since it is the mystical bread "coming down from heaven."”
“And because that Christ, our Redeemer, declared that which He offered under the species of bread to be truly His own body, therefore has it ever been a firm belief in the Church of God, and this holy Synod doth now declare it anew, that, by the consecration of the bread and of the wine, a conversion is made of the whole substance of the bread into the substance of the body of Christ our Lord, and of the whole substance of the wine into the substance of His blood; which conversion is, by the holy Catholic Church, suitably and properly called Transubstantiation.”
“For what now lies beneath the aforementioned species is not what was there before, but something completely different; and not just in the estimation of Church belief but in reality, since once the substance or nature of the bread and wine has been changed into the body and blood of Christ, nothing remains of the bread and the wine except for the species…”
“By the consecration the transubstantiation of the bread and wine into the Body and Blood of Christ is brought about. Under the consecrated species of bread and wine Christ himself, living and glorious, is present in a true, real, and substantial manner: his Body and his Blood, with his soul and his divinity”