How St. Irenaeus Clarified Key Church Teachings

Saint Irenaeus refuted heretics and emphasized the Real Presence of Christ in the Holy Eucharist, and apostolic succession and the role of the pope.

Statue of St. Irenaeus at the Église de la Madeleine in Paris
Statue of St. Irenaeus at the Église de la Madeleine in Paris (photo: Guillaume Baviere/CC BY 2.0/Wikimedia Commons)

In a recent article at the Register, I began to speak about the life and work of Saint Irenaeus (A.D. 140-202), in light of the movement to have him named a Doctor of the Church by some episcopal conferences around the world, including our own here in the United States of America.

I had mentioned that Irenaeus and some of the other Church Fathers never received the title of “Doctor of the Church” because they were considered martyrs. And yes, here I must acknowledge that there is some debate as to whether or not Irenaeus actually was martyred for the faith. Some claim that there is no actual proof that Saint Irenaeus was actually martyred by his persecutors. However, I will state that Irenaeus’ martyrdom has been attested to by no less an authority that Saint Gregory of Tours in his History of the Franks (1.29) and that it is the longstanding tradition in our Church to hold that Saint Irenaeus was actually a martyr. In fact, as I stated in a previous article, this is how he is celebrated in the liturgy — as a Bishop and Martyr.

With this being said, in order to emphasize some of the more important contributions of this great saint, I would like to discuss some key themes that Irenaeus discussed and helped the early Church clarify. These would include an appreciation of the Holy Eucharist as the Real Presence of Christ, apostolic succession and the role of the pope, and his key apologetics against heretics — something from which we can learn today.

As we know, an understanding of the Real Presence of Christ in the Eucharist was always part of our Catholic faith, coming directly from Christ himself in the Scriptures. What it means to have Christ sacramentally present in the Eucharist, coming up with a proper understanding of the Real Presence and a proper articulation of this belief, grew and developed over the centuries. In the early Church, the heresy of Docetism arose and, at its essence, this heresy meant that Jesus, being divine, only appeared or “seemed” (which is what dokeĩn means in Greek) to be human. Jesus’ human body was merely a phantasm — not that of a real man, who suffered, died and was buried. Other forms of Docetism held that Jesus was a normal human being, but, at the baptism in the River Jordan by John, the Divine Logos entered this man, giving him his Christ-like abilities. It should be noted that the Council of Nicea (A.D. 325) definitively condemned Docetism.

Some key early Church Fathers in the age directly after the apostles — Saints Justin the Martyr and Ignatius of Antioch among them — fought against this heresy and those that arose alongside of it. For these Fathers, belief in Christ’s Presence in the Eucharist was tied to a belief in Christ’s Incarnation, his taking of real human flesh, becoming a man like us in all things but sin. Saint Ignatius of Antioch in his Letter to the Smyrnaeans (7.1) describes these misguided Christians abstaining from the celebration of the Eucharist because they did believe in the Incarnation. Saint Ignatius writes:

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. They who deny the gift of God are perishing in their disputes.

As we shall see, one of the forms of Gnosticism that Saint Irenaeus needed to battle against denied the actual goodness of the human flesh. Connecting the Incarnation of Christ into belief in the Real Presence, Saint Irenaeus states:

Those who reject the whole “economy” of God, deny the salvation of the flesh and reject its regeneration, saying that it is not capable of receiving imperishability, are absolutely vain. If this flesh is not saved, the Lord did not redeem us by his blood (Col 1:14) and the cup of the Eucharist is not communion with his blood and the bread we break is not communion with his body (1 Cor 10:16). For blood comes only from veins and flesh and the rest of the human substance, which the Word of God became when he redeemed us by his blood. As his Apostle says, “In him we have redemption by his blood, the remission of our sins.” (Col 1:14). And because we are his members (1 Cor 6:15) and are nourished by means of the creation (which he himself provides, making his sun rise and raining as he will [Matt 5:45]), he declared that the cup from the creation is his blood, out of which he makes our blood increase, and the bread from the creation is his body, out of which he males our body grow. (Against the Heresies Lib. 5, cap. 2,2 as found in Robert M. Grant, Irenaeus of Lyons, The Early Church Fathers, London: Routledge, 1997, 164])

He goes on to state:

If then the cup of mixed wine and the bread that is made receives the word of God and becomes the Eucharist of the blood and the body of Christ, and from these it grows and consists of the substance of our flesh, how can they deny that the flesh is receptive of the gift of God, which is eternal life , when it has been nourished by the body and blood of the Lord and is a member of him? When the blessed Apostle said in the letter to the Ephesians, “that we are members of the body, of his flesh and his bones” (Eph. 5:30), he was saying these things not of some spiritual and invisible man (“For a spirit does not have bones or flesh”) [Luke 24:39] but of the real man’s constitution, consisting of flesh and sinews and bones, which is nourished from the cup, which is his blood, and grows from the bread, which is his body. (Against the Heresies Lib. 5, cap. 2,2 as found in Robert M. Grant, Irenaeus of Lyons, The Early Church Fathers, [London: Routledge, 1997, 164])

Finally, concerning the Real Presence of Christ found in the Eucharist, Irenaeus writes:

Just as cutting from a vine, planted in the earth, bears fruit in due season, and a grain of wheat, falling on the ground therein dissolves, and rises again with large increase by the Spirit of God who sustains all things, and thereafter, by the Wisdom of God, becomes fit for man’s food, and at last receives the Word of God and becomes a Eucharist, which is Christ’s Body and Blood, so too our bodies, nourished by the Eucharist, and laid in the earth there to suffer dissolution, will in due season rise again. (Against the Heresies Lib. 5, cap. 2,3 in Patrologia Greca 7, 1127.)

This past summer, on July 23, 2019, the Pew Research Center, a rather reputable organization, released the results of a survey titled:  “What Americans Know About Religion.” This survey reported that half of Catholics in the United States don’t seem to know that the Catholic Church teaches the Eucharist is the actual Body and Blood of Jesus Christ and that the majority of the other half thought the Church taught the Eucharist was just a symbol of Christ’s body, with 4% stating they were unsure what the Church taught on the subject. Sixty-nine percent of those polled believed only that the Eucharist was a symbol of Jesus. Twenty-two percent of those polled (and who stated that they knew the Church’s teachings on the Eucharist) stated that they actually reject the concept of transubstantiation. Only 31% report that they believe that “during Catholic Mass, the bread and wine actually become the body and blood of Jesus.” (The results can be found at this website.)

With this in mind, imagine hearing the words of Irenaeus on this topic — so clear, so fiery, so tied into the Lord’s own divinely revealed testimony as found in Sacred Scripture today, from our pulpits at our Masses, Sunday after Sunday! We need to reclaim a patristic style of preaching, one that is tied closely to the testimony of the Scriptures, one that is addressing the needs and questions of the community and thus is pastoral. (Recall that almost all of the Fathers were bishops and pastors, writing not for some academic audience, but in response to needs of the people.) Irenaeus’ wisdom in connecting belief in Christ in the Incarnation and belief in Christ in the Eucharist is one on which we need to reflect, especially in the Christmas season when we celebrate the Nativity of our Lord.

In my next piece, I wish to discuss the contribution of Saint Irenaeus on the question of apostolic succession and then, in the final piece in this series on Irenaeus, we shall discuss the heresies that still plague the world today which this great possible Doctor of the Church can help address.