Irenaeus of Lyons

About a year ago my family and I visited a Seventh-day Adventist church on the South Side of Chicago. After the service we stayed for potluck, and while eating Spanish rice with mushroom sauce and avocado, the elder sitting across from me asked what my occupation was. After learning that I study the early Church Fathers, he looked at me with a confused look, then turned to his wife, who also seemed perplexed, and they both hesitatingly asked me, “But are those not Catholic saints?”

That was not the first time I’d been asked that question in one form or another. The concern is always: Why am I, a Seventh-day Adventist, studying such figures as Irenaeus, who are venerated as saints in faith confessions that are different from my own?

It is a fair question, and one that deserves a thoughtful answer. As Seventh-day Adventists, we believe in Scripture alone as our final authority. So why would we study someone from the second century whose church looked different from ours?

Here is what I have discovered: In reading Irenaeus, I find a Christian wrestling with Scripture to defend truths we still hold precious today—Christ’s full divinity and humanity, the goodness of God’s creation, and salvation through Christ alone. I do disagree with his teaching on apostolic succession, but I think that both agreements and disagreements help us to dig deeper and become more anchored in what we believe and why we believe it. So allow me to introduce you to this ancient defender of biblical Christianity and attempt to demonstrate why his voice matters today.

Who was Irenaeus of Lyons?

Irenaeus lived from approximately A.D. 130 to 202. As a young man in Smyrna (modern-day Izmir, Turkey), he studied under Polycarp, who was a disciple of the apostle John. Irenaeus later became bishop of Lyons, Gaul (modern-day Lyon, France), a city with a Christian community that faced both external persecution and internal doctrinal threats. The greatest threat came from Gnosticism, a complex religious movement that claimed to possess a secret, spiritual knowledge beyond what ordinary Christians understood. Gnostic teachers taught that Christ was a divine being who possessed the body of the man Jesus at baptism, and left right before the cross, so Christ was never human. They also insisted that the world was created by an inferior deity who had fallen far from God the Father, hence physical creation is evil, and souls are seeking escape to ascend to God. As such, salvation came through esoteric knowledge rather than faith in Christ’s redemptive work.

Imagine believing that the God of the Old Testament, the Creator who called His work “very good,” was an ignorant impostor. Imagine thinking your body was a prison from which your soul needed escape. This is what Gnostic teachers were telling Christians, and it undermined basic Christian tenets: the incarnation, the resurrection of the body, and the hope of a new earth.

In response, Irenaeus wrote his masterwork, Against Heresies, to counter Gnostic claims. Through sustained engagement with Scripture, Irenaeus taught that God is the creator of the world, that Christ became a human being to conquer where Adam failed, and that our salvation depends on God becoming human to be effective. Let’s explore in closer detail these teachings.

Irenaeus’ Cosmology[1]

Against Gnostic speculation that the material world was created ignorantly by an inferior deity through a catastrophe, Irenaeus insisted, drawing on Genesis 1 and 2, that the creation of the world was the purposeful and delightful plan of God the Father. He said, “It is He who through Himself created and adorned and contains all things. Now, ‘all things’ includes us and this world of ours. And so we too, together with all things the world contains, were made by Him.”[2]

Irenaeus’ witness reminds us that our Christology stands in continuity with Christians who studied Scripture, even if it is in a distant past.

Irenaeus also understood from Genesis 1:26 and 2:7 that God made man in His image, according to His own will and for His own purpose, and as such, He has contingency plans in place to save His creation should the latter derail from His plan and purpose. He affirms, “The flesh, which in the beginning accepted God’s skill, will be found capable of receiving and accepting God’s power.”[3] This is important because, for Irenaeus, God can also redeem matter, and redemption could occur only through the Incarnation.

Irenaeus’ View on the Incarnation

Irenaeus consistently appealed to John 1:1-14 to show that the eternal Word who was God became flesh and dwelt among us. He drew on Philippians 2:5-11 to demonstrate that Christ, although being God, took on the form of a human servant and became obedient to death. When Gnostics claimed that the divine Christ merely appeared human or temporarily inhabited the man Jesus, Irenaeus responded with Scripture’s clear testimony. He wrote:

“It was not possible for humankind, which had once been conquered and had been dashed to pieces by its disobedience, to refashion itself and obtain the prize of victory. Again, it was not possible for the human race, which had fallen under sin, to receive salvation. And so the Son, Word of God that He is, accomplished both, by coming down from the Father and becoming incarnate, and descending even to death, and bringing the economy of our salvation to completion.”[4]

Irenaeus placed humanity as trapped between being defeated and unable to save itself, so Christ became human to gain our victory over Satan and restore our salvation. The best way that Irenaeus could capture Christ’s humanity was through His suffering. Drawing from Paul’s testimony,[5] Irenaeus concludes:

“Thus he [Paul][6] points out that it was not an impassible Christ who descended on Jesus, but, since He was Jesus Christ, He Himself suffered for us; He who lay in the tomb also rose again; He who descended also ascended, the son of God having been made man, as the very name indicates.”[7]

What Irenaeus means is that if Christ wasn’t truly human, His suffering was an illusion and His example meaningless. If Christ wasn’t truly divine, His sacrifice couldn’t save us. Both aspects of His nature are essential to the gospel and our salvation. He stated this principle clearly: “For it behooved the Mediator of God and humanity, by His kinship to both, to lead them back to friendship and concord.”[8] In other words, Christ’s sacrifice gives us direct access to God and allows God to unite with us once again.

Irenaeus on Redemption

One of Irenaeus’ most reputed contributions is his teaching on “recapitulation”—a doctrine rooted in Romans 5, 1 Corinthians 15, and Ephesians 1:10. The Greek word anakephalaiosis means “providing a new head,” and Irenaeus used it to describe how Christ retraced and reversed Adam’s path, and thus Christ becomes our head.

Where Adam, the first man, disobeyed and brought death, Christ, the second Adam, obeyed and brought life. Where Adam failed in the garden, Christ succeeded in Gethsemane and conquered on the cross of Calvary. But this required Christ to be truly human—entering into the human condition at every stage—while also being truly divine, possessing the power to overcome sin and death. Irenaeus explains: “For He would not be a man with true blood and flesh, by which He redeemed us, unless He had recapitulated in Himself the ancient handiwork of Adam.”[9]

Knowing more about the church fathers equips us to engage in dialogue with other Christians.

In the understanding of Irenaeus, Christ validates His true humanity by going through the temptations that Adam experienced, but unlike Adam, Christ saved the whole human race with His blood, thus reuniting fallen humanity with God, the Creator. For Irenaeus, redemption was not about escaping creation but restoring it, bringing creation back to God’s original purposes.[10]

Apostolic Succession

While Irenaeus taught doctrines he took directly from Scripture, he left a nonscriptural legacy unquestioned that has impacted the church to this day—the doctrine of apostolic succession. Irenaeus believed that authentic apostolic teaching was preserved and transmitted through an unbroken succession of bishops in the churches. He traced the line of bishops in Rome back to Peter and Paul, and he argued that this succession guaranteed the preservation of true doctrine.[11]

Irenaeus’ concern was eminently practical: Gnostic teachers claimed to possess a secret knowledge handed down from the apostles that the public churches were not privy to. They claimed to have the “real truth” that Jesus supposedly taught privately. Irenaeus responded by pointing to the public, visible churches where everyone could see what had been taught from the beginning. He wrote:

“All, therefore, who wish to see the truth can view in the whole church the tradition of the apostles that has been manifested in the whole world. Further, we are able to enumerate the bishops who were established in the churches by the apostles, and their successions even to ourselves.”[12]

While Irenaeus’ teaching on apostolic succession was a practical response to teachings he believed were endangering the unity of the church and the consistency of Christ’s teachings, the implications that have trickled down to this age are consequential. Irenaeus’ apostolic teaching implied that only the top leaders of the church, the bishops in his time, had been given the authority to interpret the Scriptures. Only the bishops can understand the Scriptures, and they are the only ones who can say what the Scriptures mean on all matters. The interpretation of Scripture according to Irenaeus is not a matter of the whole church, sharing ideas in common, but the work of a separate group of people, that is, only those who can trace their appointment back to the apostles. The other corollary of this doctrine is that only the churches that have bishops who can trace their appointment back to the apostles are true, authentic Christian churches.

Observations

What difference do the teachings of Irenaeus make for us today? First, although Irenaeus of Lyons is far removed from our time today, across nearly 2,000 years his biblical defense of Christ’s full divinity and full humanity is a doctrine we agree with because we have found it in the Bible. When he argued from Scripture that salvation requires the God-man, he was defending truths we hold precious. Irenaeus’ witness reminds us that our Christology stands in continuity with Christians who studied Scripture, even if it is in a distant past.

Second, knowing more about the Church Fathers, such as Irenaeus, provides us with a historical perspective on the use of Scripture in doctrinal development. It equips us to engage in dialogue with other Christians who value these figures. And it reminds us that faithful believers throughout history have wrestled with Scripture, sought truth, and defended the gospel, just as we do today.

Third, Irenaeus shows us that, in the face of efforts to preserve biblical truth against innovation and error, the answer is found only in Scripture. Even in his mistakes we learn to return to the Bible, where truth resides, whether the situation calls for argumentative or practical solutions. Irenaeus’ concern for the preservation of unity and biblical truth leads us to a serious return to faithful biblical interpretation, corporate engagement with Scripture, and continuous reformation in accordance with Scripture.

Last, on apostolic succession, we part ways respectfully. We appreciate his concern for preserving the truth, but believe Scripture points us to a different answer: that Christ, not the bishop, is the head of the church, and that we receive our interpretation of Scripture from the Scriptures themselves. Ultimately, we could learn more about Irenaeus because, in his biblical Christology, we find a friend; in his ecclesiology, a respectful dialogue partner; and in both, an opportunity to grow in understanding and grace.

[1] I will be using the Ancient Christian Writers translation of Against the Heresies (mentioned as Haer. from here on), trans. Dominic J. Unger (New York: Paulist Press, 1992-2024).

[2] Haer. 4.20.1. See also Haer. 4.20.4; Haer. 2.1.1.

[3] Haer. 5.3.2.

[4] Haer. 3.18.2.

[5] See Rom. 14:15, Eph. 2:13, Gal. 3:13, and 1 Cor. 8:11.

[6] Bracketed material added.

[7] Haer. 3.18.3.

[8] Haer. 3.18.7. (Emphasis added.)

[9] Haer. 5.1.2.

[10] Roger E. Olson, The Story of Christian Theology: Twenty Centuries of Tradition and Reform (Downers Grove, Ill.: InterVarsity Press, 1999), p. 76.

[11] See Haer. 3.3.2.

[12] Haer. 3.3.1.