I think we should break down what you seem to be saying here.
First, there is the statement that the flesh profiteth nothing. Okay, so whose flesh does he mean? Is it the flesh that he just spent about thirty verses commanding us to eat if we would have life? That flesh which would soon hang on a cross, rise up in three days, and ascend into heaven? Is that the flesh which you believe he says “profiteth nothing?” If so, then you are still in sin since that flesh couldn’t profit you redemption and salvation.
Next, we have the references to the spirit. I take by these you would think he means only a spiritual reality, which would perhaps be symbolic or figurative, and obviously must be less than literal. So, again I would ask which spirit does he mean? He says it quickeneth which means it gives life. I can tell you which Spirit that sounds like to me. What do you think? And would that mean that the Spirit is only a symbolic reality? Would you say that any scriptures about the Spirit are not literal teachings, but only figurative ones? And, are even spiritual things symbolic? Is a spiritual truth somehow less real than an earthly one? Just how does spirit equal a symbolic or figurative meaning rather than a literal one?
No, this says nothing at all about denying a literal understanding. His words were both spirit and life, and he meant them. The flesh which profits nothing, of course, is that which is not enlivened by the Spirit. That would be carnal flesh, or those who heard him and rejected him. They are carnal, and of this world, and they heard him as flesh without the Spirit and so rejected him. They can only think he meant canibalism, because that is all they can hear. They did not hear as the Apostles did. They surely did not understand either, but they heard in faith and trust, knowing that he had the words of eternal life.