One must read past a singular scripture in order to recognize John 6: 38 is part of a holy and sacred grace filled gift plan for which God entered the world as Christ Jesus, Emmanuel, meaning "God with us", so as to fulfill what harmonizes with John 6 and can be seen prior to that Book in the
Book of John chapter 3. And particularly verse 16. Which describes Christ's purpose and the reason He was begat into this world. While John chapter 6 fully explains, through Christ's own preaching, the full import of why He is in the world.
And it all has to do with God's irrevocable grace. And Jesus' teaching that would lead those for whom it resonates to come to faith in a Salvation doctrine wherein the blood of bulls and goats and other animals , would no longer be necessary so as to repent and cover one's sin.
Rather, the blood of that final perfect unblemished lamb without sin, Jesus the Christ, would be spilled on that last sin altar, the cross, so as to cover for eternity the sins of the world. And what is required of the individual who hears this message and recognizes they are a sinner, living contrary to what God's righteous vision of them and their lives at their fullest potential that can be lived in His grace?
Crucifixion of themselves, as Jesus died?
No!
Faith! Just faith. Beliefin Jesus and what He died for and what that means and transfers unto
whosoever believes in Him.
That's not work, to believe. That's trust that the creator of all things made a gift unto you that will last eternally and that He will never revoke, take back.
That is our God of the Bible!
The Book of John Chapter 6
22 On the morrow the multitude that stood on the other side of the sea saw that there was no other [
e]boat there, save one, and that Jesus entered not with his disciples into the boat, but
that his disciples went away alone 23 (howbeit there came [
f]boats from Tiberias nigh unto the place where they ate the bread after the Lord had given thanks): 24 when the multitude therefore saw that Jesus was not there, neither his disciples, they themselves got into the [
g]boats, and came to Capernaum, seeking Jesus. 25 And when they found him on the other side of the sea, they said unto him, Rabbi, when camest thou hither? 26 Jesus answered them and said, Verily, verily, I say unto you, Ye seek me, not because ye saw signs, but because ye ate of the loaves, and were filled. 27 Work not for the food which perisheth, but for the food which abideth unto eternal life, which the Son of man shall give unto you: for him the Father,
even God, hath sealed. 28 They said therefore unto him, What must we do, that we may work the works of God? 29 Jesus answered and said unto them, This is the work of God, that ye believe on him whom [
h]he hath sent. 30 They said therefore unto him, What then doest thou for a sign, that we may see, and believe thee? what workest thou? 31 Our fathers ate the manna in the wilderness; as it is written, He [
i]gave them bread out of heaven to eat. 32 Jesus therefore said unto them, Verily, verily, I say unto you, It was not Moses that gave you the bread out of heaven; but my Father giveth you the true bread out of heaven. 33 For the bread of God is that which cometh down out of heaven, and giveth life unto the world. 34 They said therefore unto him, Lord, evermore give us this bread. 35 Jesus said unto them, I am the bread of life: he that cometh to me shall not hunger, and he that believeth on me shall never thirst. 36 But I said unto you, that ye have seen me, and yet believe not. 37 All that which the Father giveth me shall come unto me; and him that cometh to me I will in no wise cast out.
38 For I am come down from heaven, not to do mine own will, but the will of him that sent me. 39 And this is the will of him that sent me, that of all that which he hath given me I should lose nothing, but should raise it up at the last day. 40 For this is the will of my Father, that every one that beholdeth the Son, and believeth on him, should have eternal life; and [j]I will raise him up at the last day.
Remember the
Book of Genesis chapter 1, God created man in His image and likeness.
"Genesis 1:26, God said, “Let Us make man in Our image, according to Our likeness”—the plural “Us” and “Our” denoting both God the Father and the Word who would later be born in the flesh as Jesus Christ (John 1:1-14). What is meant by God’s
image and
likeness here?
...The word tselem (“image”) has the sense of a statue, while demuwth (“likeness”) refers to
physical resemblance. Yet, as John 4:24 John 4:24 God is a Spirit: and they that worship him must worship him in spirit and in truth. American King James Version × tells us, “God is spirit.” "
The Likeness of God
Now, reading just what is excerpted from that source above that tells you about God's creation of the first people, the entire human race, review what Calvinism tells you God must be as refers to image and likeness according to the God of Calvinism's creation of those humans whom He made in that image and likeness of Himself, as per Calvinism, we recall God predetermined all things before any thing came to exist. God augmented the image and likeness of man according to plan. But that can only be possible if God is that image and likeness that Total Depravity describes and then fulfills as all of humanity that came to exist
after and through fallen Adam and Eve.
All men have inherited the sin of Adam through their parents and are morally unable to choose to follow God and be saved because of their own depraved, sinful nature which extends to every part of their personality. 
