Dennis Minns sets out a brief introduction of Irenaeus by following his polemical arguments in Against Heresies. This document is Irenaeus’ refutation of the Gnostic tradition as espoused by Valentinus, as well as, the Marcionites, who differentiated between the God of the Old Testament and the God of Jesus, as per Marcion. By following Irenaeus’ arguments, Minns hopes to establish the ancient writer’s overarching theology, even though it far from a systematic work. Minns uses this approach for Irenaeus since much of his biography is unknown and speculative at best.
Due to the limited information concerning Irenaeus’ life, Minns suggests that Irenaeus must be understood in light of his polemic. In other words, Irenaeus’ theology is forged in response to the “heretics” of the early Church. Although Irenaeus does respond to the Gnostic problem, it is difficult to imagine this then qualifies him solely as a “polemical theologian.” This label suggests his theology is merely response and reaction. Plus, it suggests that it is entirely negative (i.e., “it is not this but this”). I find this a difficult category to adequately contain the whole of Irenaeus’ work and legacy for the Church. After all, Irenaeus helped form the canon and the regula fidei as guides for the Church.
We should remember that Irenaeus’ theology was formed under the tutelage of Polycarp long before Against Heresies was written. In other words, Irenaeus’ theology is well-formed by the time he actually set out to respond to the Gnostics. Furthermore, with so little knowledge about Irenaeus’ total life, it may be unfair to label him solely as a “polemical theologian” based on his limited writings. As a “man of peace”, it could be that Irenaeus was much more than a “polemical theologian.” In fact, Irenaeus’ “polemic response” may be more out of concern for unity than orthodoxy (although right doctrine is important).
Irenaeus’ primary concern in Against Heresies is combating the false doctrine of Gnosticism. Gnostics bifurcated all of life into spirit and flesh. The body and everything material was considered evil and corrupted. The spirit, on the other hand, was considered pure and good. Those that had received special revelation were given the ability to transcend the material and would inherit eternal life in a disembodied heaven. Irenaeus’ theological response to this issue is a great contribution to the Church. We are both “dust and spirit or breath.” We are both physical and spiritual creatures. We cannot be human without both of those present.
Irenaeus outright rejects the Gnostic notion for several reasons. His most powerful arguments center on the fact that to be human is to be embodied and part of the material world, despite its broken state. We are all the progeny of the first Adam because we have been molded from the same mud by God’s hand. Furthermore, God’s economy of salvation is established and completed in the work of Christ who is the second Adam. Through Christ we participate in the new life of resurrection, which will be a bodily resurrection.
The grace of God available through the sacraments of the Church attests this bodily redemption. Baptism cleanses the body and the Eucharist allows us to receive Christ’s body into our own bodies. By being joined with the glorified body of Christ, our bodies, too, are glorified by the Father. Irenaeus employs the Scriptural notion of “recapitulation” to describe this reality. Christ’s participation in our humanity makes way for our participation in his glorification.
Marcion believed that the Creator God of the Old Testament was different than the loving God that Jesus claimed as Father. As such, Marcion omitted the Old Testament and heavily redacted the New Testament in light of this conviction. Conflicting views in the New Testament were harmonized or done away with altogether. This violates Jesus’ own words that he came “to fulfill the Law and the Prophets.” John’s Gospel, which was also popular among the Gnostics, connects the Logos (Christ) with the Creator God of Genesis 1.
Again, Irenaeus went to task against Marcion’s understanding. Irenaeus integrally linked the economy of creation and salvation together. Thus, the first creation is fundamentally a part of the new creation that will be ushered in with the New Jerusalem. God’s Creation was created “good” not evil. In other words, the work of the Creator God in the Old Testament cannot be separated from the work of Jesus’ Father in the New Testament. Irenaeus will go on to point out that there is only One True God in Three Persons.
There are not two gods, as the Gnostics and the Marcionites suggest. Rather, there is only the One True God whose image is Christ. Although Irenaeus tends to emphasize Jesus’ humanity, he does not do so to the detriment of Jesus’ relationship as Son to the Father. Jesus is divine as well as human. He is conceived by the Holy Spirit and born of the same mud as Adam through Mary. This is an essential response to particular forms of Gnosticism, especially under Marcion, that conceived of as Jesus being fully human but adopted as God’s son. Irenaeus holds Jesus’ humanity and divinity in full tension.
Thus, in Christ both divinity and humanity are brought together. Recapitulation of Christ as the second Adam bridges the gap between the “vengeful God” of the Old Testament and the “loving God” of the New Testament. It is in the person of Christ that the full manifestation of the Word of God, God’s character and nature, are on full display for us to know and see. And, at Jesus’ second coming, Irenaeus argues, we shall come to full maturity. This is participatory language. Through Christ’s participating in humanity, humanity participates in the very life of God – Father, Spirit, and Son.