Jesus identified HIS FLESH as the Bread which DESCENDS OUT OF HEAVEN. The Trinitarian interpretation of John 6:38 does not fit this fact and contradicts this fact. Unless you can clearly explain how HIS FLESH is the bread which DESCENDED OUT OF HEAVEN, your predicament remains since that is precisely what Jesus described the bread IS.
Believers are taught by God through His word, the risen Jesus. His sheep hear his voice. The Spirit of Truth leads them into all the truth. Spiritual ones discerning spiritual things (1 Corinthians 2:13). If you have creedal doctrines or traditions to serve, do not suppose you will receive anything from the Lord. You cannot serve both the Lord and your man made creeds. You cannot serve two masters or you will love the one and hate the other. You must choose which you will serve. Will you serve man-made doctrines or creeds or traditions, or will you serve the Lord? Because if the Lord teaches you something which does not serve your creed or your doctrines, what then will you do? Who then will you serve? Most choose their creedal traditions and so they learn nothing from the Lord.
Believers are born of God, born of the Spirit from above, born of the Spirit that descended out of heaven, born from above. They are from God in heaven. The old man has died together with Christ, the new man is born, born of God our Father who art in heaven, born into his resurrection life above. WHO these fleshly humans were is gone; WHO these fleshly humans are, has descended out of heaven in the Spirit of the Living God. This is why the world does not know them (1 John 3:1). Nothing changes about WHAT they are, at least until the resurrection the last day. What changes is WHO they are and WHO they are is defined by what they DO - they walk according to the Spirit of Christ in them. And this is why the world does not understand what Jesus is talking about in John 6. If you understand those things, you will understand Jesus in John 6 and you will understand him with total clarity. God's gifts are for anyone and He is no respecter of persons. He gives His Holy Spirit to those who obey Him, and so serve Him, not to those who insist upon obedience to their creeds and traditions. and to serve them. Choose what you will serve and choose wisely.