Jesus said to them, Amen, amen, I say to you, unless you eat the flesh of the Son of Man and drink his blood, you do not have life within you. Whoever eats my flesh and drinks my blood has eternal life, and I will raise him on the last day. For 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 6:53-57)
While they were eating, Jesus took bread, said the blessing, broke it, and giving it to his disciples said, Take and eat; this is my body. Then he took a cup, gave thanks, and gave it to them, saying, Drink from it, all of you, l for this is my blood of the covenant, which will be shed on behalf of many for the forgiveness of sins.
(Matt 26:26-28)
For I received from the Lord what I also handed on to you, that the Lord Jesus, on the night he was handed over, took bread, and, after he had given thanks, broke it and said, This is my body that is for you. Do this in remembrance of me. In the same way also the cup, after supper, saying, This cup is the new covenant in my blood. Do this, as often as you drink it, in remembrance of me. For as often as you eat this bread and drink the cup, you proclaim the death of the Lord until he comes. Therefore whoever eats the bread or drinks the cup of the Lord unworthily will have to answer for the body and blood of the Lord. A person should examine himself, and so eat the bread and drink the cup. For anyone who eats and drinks without discerning the body, eats and drinks judgment on himself.
(1 Cor 11:23-29)
In that very same chapter of John our Lord also says,
Jhn 6:38 For I have come down from heaven, not to do my own will but the will of him who sent me.
Jhn 6:39 And this is the will of him who sent me, that I should lose nothing of all that he has given me, but raise it up on the last day.
Jhn 6:44 No one can come to me unless the Father who sent me draws him. And I will raise him up on the last day.