Flesh ≈ anything that can be quantified by your mind, appearing and subsiding in time: people, places, things;
including thoughts, feelings, memories.

eating of the flesh = absorbing the teaching; not yet born of the spirit
You, however, are not in the flesh but in the Spirit, if in fact the Spirit of God dwells in you. Anyone who does not have the Spirit of Christ does not belong to him.
Romans 8:9
For all who are being led by the Spirit of God,
these are sons of God.
Romans 8:14
The Spirit itself beareth witness with our spirit, that we are
the children of God
Romans 8:16
And as we have borne the image of the earthy, we shall also
bear the image of the heavenly.
1 Corinthians 15:49
Since we are living by the Spirit, let us follow the Spirit’s leading in every part of our lives.
Galatians 5:25
The wind blows wherever it pleases.
You hear its sound, but you cannot tell
where it comes from or where it is going.
So it is with everyone born of the Spirit.
John 3:8
The Spirit alone gives eternal life. Human effort accomplishes nothing. And the very words I have spoken to you are spirit and life.
John 6:63
Now the Lord is that Spirit: and where the Spirit of the Lord is, there is liberty.
2 Corinthians 3:17
Except the LORD build the house, they labour in vain that build it: except the LORD keep the city,
the watchman waketh but in vain.
Psalm 127:1
Very truly I tell you, no one can see the kingdom of God unless they are born again.
John 3:3
Are you so foolish?
After beginning by means of the Spirit, are you now trying to finish by means of the flesh?
Galatians 3:3
He that eateth my flesh, and drinketh my blood, dwelleth in me, and I in him.
John 6:56
So it is written:
“The first man Adam became a living being”;
the last Adam, a life-giving spirit.
1 Corinthians 15:45
“Two nations are in your womb, and two peoples from within you will be separated; one people will be stronger than the other, and the older will serve the younger.”
Genesis 25:23