Eats My Flesh and Drinks My Blood

What did we already establish Jesus meant by “one who eats My flesh” (John 6:54)?
One who feeds on His Word (see I am the Bread of Life).

Where was Jesus' “blood” (John 6:54) shed?
On the cross.

So what does Jesus mean by His “blood” (John 6:53-56)?
His sacrificial death on the cross for our sins: “For this is My blood of the new covenant, which is poured out for many for the remission of sins.” (Matthew 26:28)

So what does Jesus mean by “The one who ... drinks My blood has everlasting life” (John 6:54)?
To have everlasting life, we must believe that Jesus' died on the cross to pay the death penalty due for our sins. Notice that Jesus is not telling them to view or acknowledge His “blood” from afar but to ingest - intake - this for ourselves.

What did He also mean by “My flesh”?
His body broken on the cross as He died to save us: “Take, eat; this is My body which is broken for you” (1 Corinthians 11:24).

Let's pull it together. What is Jesus saying we must do to have “everlasting life” (John 6:40, 47, 54)?
Believe in Him as per His Word, which is in the Bible, and believe that His sacrificial death on the cross paid the death penalty due for our sins.

Do you?
 

What does Jesus mean by “the one who feeds on Me shall live by Me” (John 6:57)?
δι/δια (dia), the original Greek word translated “by,” means both “by way of” and “because of.” Jesus isn't just the modality of how we live; Jesus is the reasons for our existence. We live because of Jesus.

Do you?
 

How important is the rest of your life vs. living “forever” (John 6:58)?
(100 - your age) / infinity = ?