Why the heck should any Christian believe that Jesus was only speaking symbolically in Scripture about his body and blood in John 6 and Luke 22 when the earliest Church leaders (bishops) believed and acted otherwise?
It doesn’t get any clearer or earlier than St. Ignatius’ (died by 117 AD) denunciation of the Docetic heretics in his letter to the Smyrnaeans:
They abstain from the Eucharist and from prayer, because they confess not the Eucharist to be the flesh of our Savior Jesus Christ, which suffered for our sins, and which the Father, of His goodness, raised up again. Those, therefore, who speak against this gift of God, incur death in the midst of their disputes. But it were better for them to treat it with respect, that they also might rise again. It is fitting, therefore, that you should keep aloof from such persons, and not to speak of them either in private or in public, but to give heed to the prophets, and above all, to the Gospel, in which the passion [of Christ] has been revealed to us, and the resurrection has been fully proved. But avoid all divisions, as the beginning of evils. (emphasis mine)
More evidence from Ignatius’ letter to the Romans:
I have no delight in corruptible food, nor in the pleasures of this life. I desire the bread of God, the heavenly bread, the bread of life, which is the flesh of Jesus Christ, the Son of God, who became afterward of the seed of David and Abraham; and I desire the drink of God, namely His blood, which is incorruptible love and eternal life. (emphasis mine)
This last citation of St. Ignatius in his letter to the Philadephians is less explicit but still supportive:
Take heed, then, to have but one Eucharist. For there is one flesh of our Lord Jesus Christ, and one cup to [show forth ] the unity of His blood; one altar; as there is one bishop, along with the presbytery and deacons, my fellow-servants: that so, whatsoever you do, you may do it according to [the will of] God. (emphasis mine)
St. Justin Martyr (died circa 165 AD) is also very explicit in his First Apology:
And this food is called among us Εὐχαριστία [the Eucharist], of which no one is allowed to partake but the man who believes that the things which we teach are true, and who has been washed with the washing that is for the remission of sins, and unto regeneration, and who is so living as Christ has enjoined. For not as common bread and common drink do we receive these; but in like manner as Jesus Christ our Saviour, having been made flesh by the Word of God, had both flesh and blood for our salvation, so likewise have we been taught that the food which is blessed by the prayer of His word, and from which our blood and flesh by transmutation are nourished, is the flesh and blood of that Jesus who was made flesh. For the apostles, in the memoirs composed by them, which are called Gospels, have thus delivered unto us what was enjoined upon them; that Jesus took bread, and when He had given thanks, said, “This do in remembrance of Me, (Luke 22:19) this is My body;” and that, after the same manner, having taken the cup and given thanks, He said, “This is My blood;” and gave it to them alone. (emphasis mine)
St. Irenaeus (died circa 200 AD) is also very clear in upholding transubstantiation in his rebuke of heretics:
But how can they be consistent with themselves, [when they say] that the bread over which thanks have been given is the body of their Lord, and the cup His blood, if they do not call Himself the Son of the Creator of the world, that is, His Word, through whom the wood fructifies, and the fountains gush forth, and the earth gives “first the blade, then the ear, then the full grain in the ear.” Then, again, how can they say that the flesh, which is nourished with the body of the Lord and with His blood, goes to corruption, and does not partake of life? Let them, therefore, either alter their opinion, or cease from offering the things just mentioned. But our opinion is in accordance with the Eucharist, and the Eucharist in turn establishes our opinion. For we offer to Him His own, announcing consistently the fellowship and union of the flesh and Spirit. For as the bread, which is produced from the earth, when it receives the invocation of God, is no longer common bread, but the Eucharist, consisting of two realities, earthly and heavenly; so also our bodies, when they receive the Eucharist, are no longer corruptible, having the hope of the resurrection to eternity. (emphasis mine)
The Didache (written 100 AD) says:
But let no one eat or drink of your Thanksgiving (Eucharist), but they who have been baptized into the name of the Lord; for concerning this also the Lord has said, Give not that which is holy to the dogs. (emphasis mine)
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