Final answer:
The Catholic belief that the bread and wine truly become the Body and Blood of Christ during the Eucharist is called Transubstantiation, which differs from the symbolic interpretation held by Protestants and particularly in the Calvinist tradition.
Step-by-step explanation:
The Catholic belief that the consecrated bread and wine are truly the Body and Blood of Christ is called Transubstantiation. This doctrine is rooted in the narrative of the Last Supper, where Jesus blessed the bread and wine, instructing His apostles to 'Take, eat; this is my body' and 'Drink from it all of you; for this is my blood of the covenant, which is poured out for the forgiveness of sins' (Matthew 26). During the Eucharist, which is also known as Holy Communion or The Lord's Supper, Catholics believe that although the bread and wine retain their accidental properties (like taste and appearance), they are substantively transformed into Christ's body and blood.
During the Divine Liturgy, this transformation of the bread and wine takes on deep significance as they become the body and blood of Christ, akin to Jesus' incarnation, when God became a human being for the salvation of the world. Protestants, by contrast, may view the bread and wine of the Eucharist primarily as symbols that commemorate Jesus' sacrifice rather than a literal transformation. The concept of Transubstantiation was distinct from the views held in the Calvinist tradition, where the Eucharist is seen as a commemorative act.