The first Mass was instituted by our Lord Jesus Christ himself at the Last Supper on the first Holy Thursday. The unbloody sacrifice of the Last Supper is a memorial of Christ’s bloody sacrifice on the cross. Thus, the mass is a unifying event of the Last Supper and Christ’s sacrifice on Calvary. Together with the mass, Christ also instituted the Sacrament of the Holy Eucharist, which is the bread and wine became His Body and Blood.