Sacraments
The Mass as True Sacrifice
The Mass is not a mere memorial meal but the one sacrifice of Christ on Calvary made sacramentally present on the altar.
Catholic teaching
Christ instituted the Eucharist as the perpetual memorial of his sacrifice, commanding the apostles to do this in his memory as priests of the New Covenant. The Mass re-presents, rather than repeats, the single sacrifice of the Cross.
Biblical foundation
Malachi foretells a pure offering among the nations, which the Fathers applied to the Eucharist. Christ's words 'do this' at the Supper use liturgical sacrificial language, and Hebrews presents him as eternal high priest.
Scripture references
Historical evidence
The Didache, one of the earliest Christian documents, already calls the Eucharist a 'sacrifice' to be offered pure. Justin Martyr identifies the bread and cup of the Eucharist with Malachi's prophesied pure offering.
The Church Fathers
“On the Lord's own day, gather together and break bread... having first confessed your sins, that your sacrifice may be pure.”