A. This eating and drinking results in everlasting life

6:27 "Do not labor for the food which perishes, but for the food which endures to everlasting life, which the Son of Man will give you" We can also think of the woman of Samaria who was told in John 4:14 that drinking the water that Christ offers would lead to everlasting life.

Eating and drinking everlasting life

6:50-51a "This is the bread which comes down from heaven, that one may eat of it and not die. I am the living bread which came down from heaven. If anyone eats of this bread, he will live forever"
6:53 "unless you eat the flesh of the Son of Man and drink his blood, you have no life in you."
6:54 "Whoever eats my flesh and drinks my blood has eternal life, and I will raise him up at the last day."

B. Believing also leads to everlasting life

3:16 "...that whoever believes in him should not perish but have everlasting life" There are many other places in the New Testament where similar things are said.

Believing everlasting life

6:40 "...that everyone who sees the Son and believes in him may have everlasting life; and I will raise him up at the last day."
6:47 "Most assuredly, I say to you, he who believes in me has everlasting life."

C. Coming to Jesus has a similar meaning

6:35 "I am the bread of life. He who comes to me shall never hunger, and he who believes in me shall never thirst." [coming and believing are put in parallel] Eating and drinking,
Believing,

Coming
everlasting life
5:40 "But you are not willing to come to Me that you may have life."
7:37 "If anyone thirsts, let him come to Me and drink. He who believes in Me, as the Scripture has said, out of his heart will flow rivers of living water."

D. Obeying/Abiding in the words of Christ

15:10 "If you keep My commandments, you will abide in My love, just as I have kept My Father's commandments and abide in His love." [This is a very important verse because it explains what it means to abide in Christ] Abiding in Christ = keeping His commandments
6:56 "He who eats My flesh and drinks My blood abides in Me, and I in him." Abiding in Christ = Eating and drinking