On the Real Presence of Jesus in the Eucharist
The Catechism of the Catholic Church teaches that the Eucharist is truly the Body and Blood of Jesus Christ (1374). In his Letter to the Smyrnaeans, Ignatius addresses the issue of those who do not believe as the Church does:
Take note of those who hold heterodox opinions on the grace of Jesus Christ which has come to us, and see how contrary their opinions are to the mind of God… They abstain from the Eucharist and from prayer, because they do not confess that the Eucharist is the Flesh of our Savior Jesus Christ, Flesh which suffered for our sins and which the Father, in his goodness, raised up again. They who deny the gift of God are perishing in their disputes. —Letter to the Smyrnaeans, Ch 6
Ignatius also explains that the Eucharist must be administered either by a bishop or one of his ordained ministers:
Let that be deemed a proper Eucharist, which is administered either by the bishop, or by one to whom he has entrusted it.—Letter to the Smyrnaeans, Ch 8
On the Authority of the Catholic Church
The Greek root of the term catholic means "according to the whole" or “universal.” Ignatius uses the term to refer to the visible and authoritative Church:
See that you all follow the bishop, even as Jesus Christ does the Father, and the presbytery as you would the apostles; and reverence the deacons, as being the institution of God. Let no man do anything connected with the Church without the bishop. Let that be deemed a proper Eucharist, which is administered either by the bishop, or by one to whom he has entrusted it. Wherever the bishop shall appear, there let the multitude of the people also be; even as wherever Jesus Christ is, there is the Catholic Church. —Letter to the Smyrnaeans, Ch 8
Ignatius urges the faithful to submit to the authority of their bishop because it is the will of God:
But inasmuch as love suffers me not to be silent in regard to you, I have therefore taken upon me first to exhort you that you would all run together in accordance with the will of God. For even Jesus Christ, our inseparable life, is the manifested will of the Father; as also bishops, settled everywhere to the utmost bounds of the earth, are so by the will of Jesus Christ… Let us be careful, then, not to set ourselves in opposition to the bishop, in order that we may be subject to God. —Letter to the Ephesians, Ch 3,5
Ignatius recognizes the authority, or “presidency,” in particular of the Church at Rome:
Ignatius, also called Theophorus, to the Church that has found mercy in the greatness of the Most High Father and in Jesus Christ, his only son; to the Church beloved and enlightened after the love of Jesus Christ, our God, by the will of him that has willed everything which is; to the Church wich also holds the presidency in the place of the country of the Romans, worthy of God, worthy of honor, worthy of blessing, worthy of praise, worthy of success, worthy of sanctification, and because you hold the presidency of love, named after Christ and named after the Father; here therefore do I salute in the name of Jesus Christ, the Son of the Father. —Letter to the Romans, Intro
Ignatius indicates that the Church at Rome possessed the authority to teach others:
You have envied no one; but others you have taught. I desire only that what you have enjoined in your instruction may remain in force. —Letter to the Romans, Ch 3Finally, Ignatius confirms—as do other Church Fathers—that this authoritative Church at Rome was founded by Peter and Paul:
Not as Peter and Paul did, do I command you. They were apostles and I am a convict. They were free, and I even to the present time am a slave. —Letter to the Romans, Ch 4
