Real Presence

At the last supper Jesus hosts the supper of the lamb. This is the eternal heavenly banquet in which Jesus is present, body and blood, soul and divinity. Jesus is both the high priest and the victim at this unbloody sacrifice of love. The Apostles, including Paul, proclaimed and lived this reality as the fundamental teaching of Christ and His Church.
Jesus demonstrated the importance of this reality when He asked the Apostles if they too wanted to leave when  many abandoned Him over this teaching. "I am the bread of life. Your fathers ate the manna in the wilderness, and they died. This is the bread which came down from heaven, that a man may eat of it and never die. I am the living bread which came down from heaven; if anyone eats of this bread, he will live forever; and the bread which I shall give for the life of the world is my flesh" John 6:48-51
Jesus stood his ground on His real presence in the Eucharist:  "My flesh is true food, and my blood is true drink. Whoever eats my flesh and drinks my blood remains in me and I in him. Just as the living Father sent me and I have life because of the Father, so also the one who feeds on me will have life because of me" (John 6:55-57). Jesus completed His sacrifice for us on the cross at Calvary, but He had already given himself to us completely and in perpetuity in the Eucharist.