At the center of the Catholic mass is the celebration of the Eucharist, or the breaking and partaking of bread and wine in community to remember Jesus’ death and resurrection. Catholic theology teaches that through the priest’s words of consecration, the conversion of the substance of the Eucharistic elements become the body and blood of Christ., although, the appearances of bread and wine remain the same.
The Eucharist is celebrated on a special table, known as the altar. The table functions as both an altar of sacrifice and a banquet table for the Eucharist, quoting St. Thomas Aquinas, says is both "a memorial of Christ's death and resurrection" and "a paschal banquet — in which Christ is eaten, the heart is filled with grace, and a pledge of future glory given to us." The bread and wine, once consecrated, remain fundamentally the holy body and blood of Christ. Any unconsumed bread or wine must either be consumed after the mass or stored in a metal box known as the tabernacle, historically on the altar. There is a Sanctuary Candle where honor is given to Christ’s body and blood. The red votive candle, known as the sanctuary lamp, is traditionally lit beside the tabernacle to show that it contains the consecrated elements. The sanctuary lamp reminds Catholics that Jesus is present in the tabernacle, and churchgoers often pray before the tabernacle and reflect on the mystery of Christ’s presence in the Eucharist.