The Eucharist is the source and summit of Catholic life. Catholics believe that during Mass, the bread and wine are transformed into the actual Body and Blood of Jesus Christ through transubstantiation — while retaining the appearance of bread and wine, their substance changes completely. This is not symbolic but the Real Presence. Jesus instituted the Eucharist at the Last Supper when He said, 'This is my body' and 'This is my blood' (Matthew 26:26-28). Receiving Communion requires being in a state of grace (free from mortal sin), observing a one-hour fast before Communion, and being a baptized Catholic. The Eucharist is both a sacrifice (re-presenting Christ's sacrifice on the Cross) and a meal (spiritual nourishment).