Just to add St John to me connects with Polycarp/St Ireneaus in this way the writing of St Ireneaus becomes intimately connected to the Church and during Easter.
Here’s Ireneaus
2.But vain in every respect are they who despise the entire dispensation of God, and disallow the salvation of the flesh, and treat with contempt its regeneration, maintaining that it is not capable of incorruption. But if this indeed do not attain salvation, then neither did the Lord redeem us with His blood, nor is the cup of the Eucharist the communion of His blood, nor the bread which we break the communion of His body. For blood can only come from veins and flesh, and whatsoever else makes up the substance of man, such as the Word of God was actually made. By His own blood he redeemed us, as also His apostle declares, “In whom we have redemption through His blood, even the remission of sins.” And as we are His members, we are also nourished by means of the creation (and He Himself grants the creation to us, for He causes His sun to rise, and sends rain when He wills ). He has acknowledged the cup (which is a part of the creation) as His own blood, from which He bedews our blood; and the bread (also a part of the creation) He has established as His own body, from which He gives increase to our bodies.
3.When, therefore, the mingled [320-321] cup and the manufactured bread receives the Word of God, and the Eucharist of the blood and the body of Christ is made, from which things the substance of our flesh is increased and supported, how can they affirm that the flesh is incapable of receiving the gift of God, which is life eternal, which [flesh] is nourished from the body and blood of the Lord, and is a member of Him?-even as the blessed Paul declares in his Epistle to the Ephesians, that “we are members of His body, of His flesh, and of His bones.” He does not speak these words of some spiritual and invisible man, for a spirit has not bones nor [322-323] flesh; but [he refers to] that dispensation [by which the Lord became] an actual man, consisting of flesh, and nerves, and bones,-that [flesh] which is nourished by the cup which is His blood, and receives increase from the bread which is His body. And just as a cutting from the vine planted in the ground fructifies in its season, or as a corn of wheat falling into the earth and becoming decomposed, rises with manifold increase by the Spirit of God, who contains all things, and then, through the wisdom of God, serves for the use of men, and having received the Word of God, becomes the Eucharist, which is the body and blood of Christ; so also our bodies, being nourished by it, and deposited in the earth, and suffering decomposition there, shall rise at their appointed time, the Word of God granting them resurrection to the glory of God, even the Father, who freely gives to this mortal immortality, and to this corruptible incorruption, because the strength of God is made perfect in weakness, in order that we may never become puffed up, as if we had life from ourselves, and exalted against God, our minds becoming ungrateful; but learning by experience that we possess eternal duration from the excelling power of this Being, not from our own nature, we may neither undervalue that glory which surrounds God as He is, nor be ignorant of our own nature, but that we may know what God can effect, and what benefits man receives, and thus never wander from the true comprehension of things as they are, that is, both with regard to God and with regard to man. And might it not be the case, perhaps, as I have already observed, that for this purpose [324-325] God permitted our resolution into the common dust of mortality, that we, being instructed by every mode, may be accurate in all things for the future, being ignorant neither of God nor of ourselves?
St Ireneaus- Against Heresies (book 5, Chapter 2 paragraph 2 and 3)
textexcavation.com/irenaeusah5.html
Irenaeus also maintained that the bishops in different cities are known as far back as the Apostles and that the bishops provided the only safe guide to the interpretation of Scripture The scripture on John is read 3rd Thursday of Easter which connects the Saint and Apostle.
usccb.org/bible/readings/041813.cfm
Gospel Jn 6:44-51
Jesus said to the crowds:
“No one can come to me unless the Father who sent me draw him,
and I will raise him on the last day.
It is written in the prophets:
They shall all be taught by God.
Everyone who listens to my Father and learns from him comes to me.
Not that anyone has seen the Father
except the one who is from God;
he has seen the Father.
Amen, amen, I say to you,
whoever believes has eternal life.
I am the bread of life.
Your ancestors ate the manna in the desert, but they died;
this is the bread that comes down from heaven
so that one may eat it and not die.
I am the living bread that came down from heaven;
whoever eats this bread will live forever;
and the bread that I will give
is my Flesh for the life of the world.”
They connect through the attack of gnostic issues.
The body of Christ and the Church is also significant in that in the presence of the Holy Spirit and the interaction of the consecration is indeed spiritually profound.