48 I am the bread of life.
49 Your fathers ate manna in the desert and they are dead;
50 This is the bread which comes down from heaven, so that a person may eat it and not die.
51 I am the living bread which came down from heaven; if any one eats of this bread, he will live for ever; and the bread which I shall give for the life of the world is my flesh.
52 The Jews then disputed among themselves, saying, “How can this man give us his flesh to eat?”
53 So Jesus said to them, “Truly, truly, I say to you, unless you eat the flesh of the Son of man and drink his blood, you have no life in you;
54 he who eats my flesh and drinks my blood has eternal life, and I will raise him up at the last day.
55 For my flesh is food indeed, and my blood is drink indeed.
56 He who eats my flesh and drinks my blood abides in me, and I in him.
57 As the living Father sent me, and I live because of the Father, so he who eats me will live because of me.
58 This is the bread which came down from heaven, not such as the fathers ate and died; he who eats this bread will live for ever.”
And then it is often pretended that Christ contradicts all this, by vs. 63:
It is the spirit that gives life, the flesh is of no avail; the words that I have spoken to you are spirit and life.
Christ does NOT contradict himself.
He means what he says in vs. 51,53,54,55,56,57,58 in His citing "my flesh".
Clearly in vs. 63 Christ refers to "the flesh" meaning human reason's inability to comprehend revealed truths apart from faith.
I do not understand your point as my LCMS believes all those verses. The LCMS is very biblical.
It is more than a symbol