[1 Corinthians 11:] [24] And giving thanks, broke, and said: Take ye, and eat: this is my body, which shall be delivered for you: this do for the commemoration of me. [25] In like manner also the chalice, after he had supped, saying: This chalice is the new testament in my blood: this do ye, as often as you shall drink, for the commemoration of me.
[Matthew 26:] [26] And whilst they were at supper, Jesus took bread, and blessed, and broke: and gave to his disciples, and said: Take ye, and eat. This is my body. [27] And taking the chalice, he gave thanks, and gave to them, saying: Drink ye all of this. [28] **For this is my blood **of the new testament, which shall be shed for many unto remission of sins.
[Luke 22:] [19] And taking bread, he gave thanks, and brake; and gave to them, saying: This is my body, which is given for you. Do this for a commemoration of me. [20] In like manner the chalice also, after he had supped, saying: This is the chalice, the new testament in my blood, which shall be shed for you.
[John 6:] [51] I am the living bread which came down from heaven. [52] If any man eat of this bread, he shall live for ever; and the bread that I will give, is my flesh, for the life of the world. [53] The Jews therefore strove among themselves, saying: How can this man give us his flesh to eat? [54] Then Jesus said to them: Amen, amen I say unto you: Except you eat the flesh of the Son of man, and drink his blood, you shall not have life in you. [55] He that eateth my flesh, and drinketh my blood, hath everlasting life: and I will raise him up in the last day.
Jesus was very clear that He is the “living bread which came down from Heaven”, the true Manna from Heaven. The bread (Holy Eucharist) that the Priest blesses and Catholics eat in commemoration of Him at every Mass, is His real flesh, and the wine is His real blood. Jesus taught the Apostles that they should always do it, so that all those who eat it can also have a share in everlasting life. If we don’t eat it, then we won’t “have life” in us. It’s the spiritual food that feeds our souls by giving us a share in Christ’s Divinity, even while we’re still here on earth.