Irenaeus – Loved by the Reformers, Still Refreshing Today

As we celebrate the 500th anniversary of the Protestant Reformation, it’s good to travel back about 1400 earlier, when a concerned pastor and missionary to today’s France sat down to write a well-informed and comprehensive work, in order to provide some clarity in his confused theological times.


Early Life and Studies

            Irenaeus’s life is hard to trace. Most scholars agree that he was born around the year 130, probably in Smyrna (today’s Izmir, Turkey), where he studied under Polycarp. In fact, the first time we can actually picture him in action is when he sat under Polycarp’s teaching, taking notes but especially committing the teacher’s words to memory, as writing tablets could easily be ruined.

            Little more than a century had passed from Christ’s ascension to his Father. All the apostles had died, and the churches they had left behind were still trying to consolidate their doctrines and practices in the middle of a proliferation of contrasting claims of Christian truth. At times, these claims sounded so outrageous that Polycarp had to cry, “O good God, for what times have you kept me, that I should endure these things?”

            Polycarp was in Rome in the year 154, where he discussed some pressing matters with bishop Anicetus. The main point of discussion was the date of Easter. The churches in the East (where Polycarp lived) celebrated Easter on the fourteenth day of the Jewish month of Nisan (which corresponded to the Jewish Passover), while the churches in the West chose to celebrate it on a Sunday, since Jesus rose from the death on that day.

            Irenaeus might have been in Rome at the same time, whether alone or as Polycarp’s companion. In any case, the final decision between Polycarp and Anicetus to “agree to disagree” taught him the importance of keeping the unity of the church in matters of faith and allowing differences in what the stoics called adiaphora and the Reformed tradition calls “things indifferent” (matters which are inconsequential to the essence of faith). In fact, Irenaeus clung to this principle later in life, when a new bishop of Rome, Victor, demanded that all Christian churches celebrate Easter on a Sunday.

            In Rome, Irenaeus came certainly in contact with Justin Martyr and other Christian apologists. He also spent time listening to dissenting voices, especially the Valentinians, a widespread community with a complicated system of beliefs. Today grouped under the general name of Gnostics, the Valentinians claimed to possess a higher knowledge that Jesus had imparted in secret to a select number of people.

            Another popular voice in Rome was that of Marcion and his followers, who had solved the theological problem of evil by stating that there are two opposing gods: a lesser god who is the creator introduced in the Old Testament, and a higher god who is the New Testament savior.


Practical Theology

            Whatever the nature of Irenaeus’s studies in Rome, his theology provided practical answers in 176, when he was called to pastor the church in Lyon, the capital of Gaul (today’s France). About a year after his arrival, the church suffered one of the worst persecutions at that time, which was well documented in a letter written to the churches in Asia. Apparently, Irenaeus escaped the persecution, maybe because he was travelling to Rome to deliver a letter to bishop Eleutherus. In any case, he was left with the difficult task of strengthening and encouraging the Christians who were still alive and had suffered such a tragic loss.

            It was not time for confused teachings. His aching church needed a robust theology, and Irenaeus provided one in both his pastoral work and his writings, exposing the errors of the Gnostics against the background of what Jude calls “the faith once delivered to the saints” (Jude 1:3).

            Sorting out the teachings of the Gnostics was an exhausting and enervating task, prompting Irenaeus to respond with the typical cries of Greek tragedies: Iou, Iou! Pheu, Pheu! He had to have, as Erasmus later commented, patient stomachi (a tolerant digestive system). Nevertheless, he persisted, for the sake of the church and also out of concern for the Gnostics, whom he loved “better than they seem to love themselves.”[1]


Irenaeus and the Reformation

            Erasmus, who edited and published the first printed edition of Irenaeus in 1526, referred to the author as “my Irenaeus.”[2] He was especially impressed by the theologian’s priscum vigorem (early vigor), a dynamism he found missing in the church of his time. Irenaeus, in fact, communicated with passion and freshness the beauty of the gospel and the Christian faith, a passion and freshness that are still standing out today. Around the end of his introduction, Erasmus prayed that God could raise some new Irenaeuses who, according to the meaning of the name (“peacemaker”), could restore peace to this world.

            Erasmus was not the only representative of the 16th century who rediscovered with joy the writings of Irenaeus. Most of the Protestant Reformers studied with zeal his writings, as well as those of other Fathers of the Church. While he was not extensively quoted, his influence was evident in Reformed doctrines, including his above-mentioned defense of freedom in “things indifferent” (a major concern in the Reformation).

            Against a background of medieval mysticism, Calvin’s emphasis on the balance provided by Deuteronomy 29:29 (“Let us then learn to make no searchings respecting the Lord, except as far as he has revealed himself in the Scriptures; for otherwise we shall enter a labyrinth, from which the retreat is not easy”[3]) echoes Irenaeus’s exhortation: “If … we cannot discover explanations of all those things in Scripture which are made the subject of investigation, yet let us not on that account seek after any other God besides Him who really exists.”[4]

            Some take this and other similar quotations to say that Irenaeus stood for Sola Scriptura. While it’s always risky to use later labels for earlier writings, Irenaeus’s emphasis on the purity of Scriptures as they had been passed down by the apostles and the predominance of biblical references in his refutation of the Gnostics speak volumes for his high regard of Scriptures as primary authority, which were summed up in the “rule of faith” confessed by Christian churches all over the then known world.

            Besides, his emphasis on the Bible as a united story (which must be understood in relation to Christ) and his view of Christianity as a historical and material faith goes well in step with the Reformation, after years of confused reading of Scriptures, mysticism and neo-platonism.

            Another theme that is prevalent both in Irenaeus and the Reformers is what Luther called a theology of the cross – a view of suffering (for Irenaeus, specifically martyrdom) as a participation in Christ’s path from cross to glory and as ultimate expression of love.

            Overall, as Westminster Seminary California graduate Nate Milne recently reminded me, the writings of the Church Fathers played an important role in the Reformation in what they didn't say. “The Reformers noted what was absent: the claims of the bishop of Rome to be the vicar of Christ and the head of the Church, purgatory, indulgences, the five additional sacraments, the withholding of the cup from the laity, the restriction of the Bible to monks and priests, the role of bishops as administrators instead of pastors, the use of an unknown language for worship, and so on.”

            Some of these are particularly evident in Irenaeus, who had no qualms correcting, together with other bishops, Rome’s bishop Victor on his imposition of a date of Easter. He also readily used the local language in his preaching and, as his Proof of the Apostolic Preaching shows, he taught his congregants the Bible (two practices which were largely lost in the medieval church).

Irenaeus Today

            Today’s Christianity has some uncanny resemblances both with the second century (in its doctrinal uncertainties and the position of the church as misunderstood minority in a pagan world) and with the mystic and neo-platonic Middle Ages. In this context, Irenaeus’s voice is as refreshing, energetic, and crisp as it was for Erasmus and the Reformers. His style is simple, clear and even humorous at times, including a great number of vivid and captivating illustrations. What’s more, his tone is deeply pastoral and cheerful, even in the middle of the dire challenges the church of his day had to face, looking not only to the joys of the world to come, but appreciating the beauty and wonders of the created world, which are for Irenaeus an expression of the goodness and love of God.

[1] Irenaeus, Against Heresies, 3.25.7,

[2] Erasmus, Divi Irenaei episcopi Opus eruditissimum, Bayerishe StaatsBibliothek Digital, p. 1

[3] John Calvin, Calvin’s Commentaries, Romans 11:33, Christian Classics Ethereal Library,

[4] Irenaeus, Against Heresies, 2.28.2, (cfr. Calvin, “Let us then learn to make no searchings respecting the Lord, except as far as he has revealed himself in the Scriptures; for otherwise we shall enter a labyrinth, from which the retreat is not easy,” Calvin’s Commentaries, Romans 11:33, Christian Classics Ethereal Library,


Simonetta Carr