What is the Eucharist — and what happens at Mass?

7 min

Awaiting theological review

The simple answer

At every Mass, the priest takes bread and wine and repeats Jesus' words at the Last Supper: This is my body… this is my blood. Catholics believe that, by the power of the Holy Spirit, the bread and wine really become the Body and Blood of Christ — not just a symbol — even though they still look and taste like bread and wine. Receiving it is called Holy Communion.

In the Bible

Scripture

At the Last Supper Jesus takes bread, gives thanks, breaks it and says it is his body, given for them; he tells them to do this in memory of him.

Luke 22:19–20

Scripture

In John 6, Jesus says he is the living bread come down from heaven, and that his flesh is true food. Many disciples leave him over these words.

John 6:51–59 · John 6:67

Scripture

Paul warns that whoever eats the bread or drinks the cup unworthily will be answerable for the body and blood of the Lord.

1 Corinthians 11:23–29

Scripture

The first Christians devoted themselves to the apostles' teaching and the breaking of bread.

Acts of the Apostles 2:42

Where it comes from

Early Christian source

Around 107, Ignatius of Antioch writes that the Eucharist is the flesh of our Saviour Jesus Christ.

Ignatius of Antioch, Letter to the Smyrnaeans 7(awaiting verification)

Early Christian source

Around 155, Justin Martyr describes the Sunday gathering: readings, a homily, prayers, bread and wine brought forward, a great prayer of thanksgiving, and communion — the same shape as the Mass today.

CCC 1345

Church teaching

The Fourth Lateran Council (1215) used the word transubstantiation; the Council of Trent (1551) explained it: the whole substance of the bread and wine becomes the Body and Blood of Christ.

What the Church teaches

Catechism

The Eucharist is the source and summit of the Christian life.

CCC 1324 Lumen Gentium, 11

Catechism

In the Eucharist, Christ is truly, really and substantially present — body and blood, soul and divinity.

CCC 1374

Catechism

The Mass does not repeat the sacrifice of the Cross: it makes present the one sacrifice of Christ.

CCC 1366–1367

Catechism

The Mass has two great parts that form one act of worship: the Liturgy of the Word and the Liturgy of the Eucharist.

CCC 1346

A common misunderstanding

Catholics believe they sacrifice Jesus again at every Mass.

In fact

Christ died once for all. The Mass makes that one sacrifice present, so that every generation can take part in it.

Why it matters today

What happens at Mass: we gather and ask forgiveness; we listen to Scripture and a homily; bread and wine are brought to the altar; the Eucharistic Prayer and the consecration; the Our Father; communion; and we are sent out. The word Mass comes from that sending.

Bible passages

Luke 22:19–20 · John 6:51–59 · 1 Corinthians 11:23–29 · Luke 24:30–35 · Acts of the Apostles 2:42

Catechism

CCC 1322–1419; 1324; 1346; 1366–1367; 1374 ↗