Unfortunately, this interpretation makes Jesus contradict himself and makes him a lousy teacher. Earlier, he already said that unless one chews on the flesh of the Son of Man, you have no life in you. And you know that Jesus cannot contradict himself. He already said that his flesh profits (that is, gives) unto eternal life.
Context therefore demands that for Jesus to not contradict himself (by taking back what he just said, and losing his disciples in the process), we must look at that “the” flesh means in v.63. In the New Testament, when “the” flesh is used in an abstract manner, it talks of pure human nature, not of the spirit. This simply points to the passage as saying, “you cannot understand what I am saying on your own, but only through the Spirit.” But this is not the way “flesh” is used in the immediately preceding verses. Rather, he identifies it as “his” flesh, not merely “the” flesh, uses it in the same context as his blood, and uses two different imperatives to command his listeners to eat (phago and trogo; trogo being the most graphic and unsuitable for symblic interpretation).
Second, never in the New Testament does spirit=symbolic.
Laudatur Iesus Christus.
I agree with the general outline of this interpretation. However, I usually think of this verse as a command to cultivate and use “the eyes of faith.”
I take the reference to “flesh” in verse 64 (63) to refer to my flesh – my senses of sight, smell, hearing, touch, and taste – which strongly urge me to disregard the Savior’s words and to think that the host is mere bread and that the cup contains mere wine.
The reference to the spirit and to the gist of what Christ said as “spirit” then seems to me to be a call to believe Jesus more than my senses, to regard the spirit (His words) as more true than the physical world (my flesh).
This seems to me to be more consistent with Jesus’ willingness to allow those to leave who found His saying too hard to hear.
It harkens to other parts of the Scriptures:
The mountains melted like wax, at the presence of the Lord: at the presence of the Lord of all the earth. Psalm 96:5 (Douay-Rheims 1899 American Edition.)
Heaven and earth shall pass away, but my word shall not pass away. Mark 13:31; Luke 21:33
This establishes the important principle that faith in the words of Jesus is more basic than belief in the report of the senses. This is important because it offers a foundation for both true religion and for empiricism. Because of this proper ordering of understanding, Jesus becomes the guarantor of the reliability of sentience – a solid basis of reliability which empiricism itself cannot offer. It is also consistent with the fundamental truth that Jesus is the one,
“Who is the image of the invisible God, the firstborn of every creature: For in him were all things created in heaven and on earth, visible and invisible, whether thrones, or dominations, or principalities, or powers: all things were created by him and in him. And he is before all, and by him all things consist. Colossians 1:15-17
Thus it is reasonable that His word about what is real is more reliable than our imperfect perception of reality through the senses. In believing this, we gain the ability to rely on our senses in their proper application. For example, sight, and touch are reliable when the Lord commands their use to St. Thomas: “Then he saith to Thomas: Put in thy finger hither, and see my hands; and bring hither thy hand, and put it into my side; and be not faithless, but believing.” John 20:27
All of this gives us a proper grasp of the role of faith in Christ as the foundation of faith in everything that has been made through Him and is maintained in being through Him. This makes both faith and reason (including empirical science) possible and reliable.
Spiritus Sapientiae nobiscum.
John Hiner