Irenaeus did not author a commentary on Genesis, as did other early Christian thinkers. Nor did he write as much about the creative activity of God as other early theologians. But no early Christian used creation to such advantage as Irenaeus of Lyons.

To appreciate what Irenaeus made of the creative activity of God it is necessary to have some sense for the moment in which he wrote. Irenaeus was made bishop of Lugdunum, a leading city in Roman Gaul—today’s Lyons, France—in the final quarter of the second century. It was a time in which there was little settled opinion and considerable philosophical and theological speculation about the nature of God and the relationship of God to the material or created world. Many Christian thinkers who lived just before and after Irenaeus, for example, did not consistently distinguish the Word of God from the Holy Spirit. They also, at times, did not distinguish the Word and Spirit from created beings. And they often left unclear whether they believed the Word and Holy Spirit to be as divine as God the Father is divine.There was little settled opinion & considerable philosophical & theological speculation about the nature of God & the relationship of God to the material or created world.

Justin Martyr, the most prominent Christian author of the mid-second century, serves as an excellent example. Twice Justin identified the Word of God and the Holy Spirit,1 Apol. 33:6 & Dial. 87-88. thereby producing a binitarian account of God which placed the Word/Holy Spirit alongside the Father. Justin also counted angels amongst those worshipped by Christians and even identified the Word and Holy Spirit as irreducible Powers—a certain class of angelic beings.1 Apol. 6, 32-33; Dial. 128.1, 4.

This identification of the Word and Holy Spirit as Powers served to distinguish them from the Father but came at the cost of blurring the line between the Word and Holy Spirit and created beings. Justin’s understanding of God was further complicated by his use of Middle Platonic terms to describe God, a practice which lends credence to the notion that his identification of the Word as the second God entails an understanding of the Word as less divine than the Father.see most recently, J. Lashier’s Irenaeus on the Trinity, Brill, 2014, pp. 60-2. Justin, then, did not consistently substantiate the diversity of God, did not completely distinguish the Three from creation, and left unclear whether he regarded the Three as equally divine. I think it fair to say that Justin believed the Three are God but could not explain how God is three.

The Distinction

It was in this context that Irenaeus brought creation to bear in his own theological account. In contrast to predecessors and contemporaries like Justin, Irenaeus used creation to distinguish the Father, Son, and Holy Spirit from that which is created, to identify the Three as the one Creator God, and to secure their distinction. In so doing Irenaeus became the first to support his belief in the Three as God with an account of God as three.
Irenaeus used creation to distinguish the Father, Son, and Holy Spirit from that which is created, to identify the Three as the one Creator God, and to secure their distinction.
Unlike Justin, Irenaeus was careful to distinguish the Creator God from that which is created. Drawing especially upon a quotation of the Greek philosopher Xenophanes, Irenaeus argued that God is simple.e.g., AH 2.13.3. That which is simple, he reasoned, is perfect. And as that which is perfect, the divine nature is not subject to increase or decrease that takes place over time. It is eternally the same. In contrast, he maintained, created beings are compound and defined by their increase and growth.AH 2.13.3, 2.28.1. This difference drives his distinction between the Creator God and the created order, as we see in Against Heresies (AH) 4.11.2:

And in this respect God differs from man, that God indeed makes, but man is made; and truly, He who makes is always the same; but that which is made must receive both beginning, and middle, and addition, and increase…. God also is truly perfect in all things, Himself equal and similar to Himself, as He is all light, and all mind, and all substance, and the fount of all good; but man receives advancement and increase towards God. For as God is always the same, so also man, when found in God, shall always go on towards God.ANF translation.

Word & Wisdom

This firm separation of the Creator God from that which is created reveals the distance that separates Irenaeus’ theological reasoning from Justin’s. But Irenaeus not only used the nature of creation to distinguish the Creator from the created order better than his contemporaries, he also used the activity of creation to establish the Father, Son, and Holy Spirit as the Creator God and to secure their distinction from each other. A quick look at a few passages will bring to light his thought. We begin with AH 4.20.1, where we find Irenaeus interpreting Genesis 1:26 and 2:7:

Those who obey him always learn that he is so great a God and that he is the very one who by himself created and made and adorned and contains all things. Now [included] among all things are both us and our world. We too, then, together with these things which are contained [by him], were made by him. And this is the one about whom Scripture said, “And God formed man, taking dust of the earth, and breathed into his face the breath of life” (Gen 2:7). Therefore, angels did not make us, nor did they form us, nor, indeed, could angels make an image of God, nor [could] any other besides the true God, nor [could] a Power far removed from the Father of all things. For God did not need these [beings] to make what he had himself beforehand determined to make, as if he himself did not have his Hands. For always present with him are the Word and Wisdom, the Son and Spirit, by whom and in whom he made all things freely and of his own will, to whom he also speaks, when he says, “Let us make man after our image and likeness” (Gen 1:26)—he himself taking from himself the substance of those things which have been created and the pattern of those things which have been made and the figure of those things in the world which have been translation.

The Triune Creator

According to Irenaeus God alone—the Father by means of his Son and Holy Spirit—created human beings. The ascription of creative activity to the Father, Son, and Holy Spirit alongside the proscription of creative activity from Powers, angels, and others reveals the firm divide Irenaeus sees between the Three and all else. There is, then, no notion in Irenaeus—as in Justin—of classifying the Son and Holy Spirit as created beings. The Father, Son, and Holy Spirit constitute the one Creator God who brings into existence all else. Still more, when read alongside the principle of divine simplicity, discussed above, Irenaeus’ identification of the Three as the one Creator God secures the equal divinity of the Father, Son, and Holy Spirit.

If their participation in creative activity identifies the Father, Son, and Holy Spirit as the one Creator God, the particular agency of each secures their distinction. In his Proof of the Apostolic Preaching 5, Irenaeus writes:

In this way, then, it is demonstrated [that there is] One God, [the] Father, uncreated, invisible, Creator of all, above whom there is no other God, and after whom there is no other God. And as God is verbal, therefore, He made created things by the Word; and God is Spirit, so that He adorned all things by the Spirit, as the prophet also says, “By the Word of the Lord were the heavens established, and all the power by his Spirit” (Ps. 33:6/32:6 LXX). Thus, since the Word ‘establishes,’ that is, works bodily and confers existence, while the Spirit arranges and forms the various ‘powers’, so rightly is the Son called the Word and the Spirit the Wisdom of God.trans. J. Behr, Irenaeus on the Apostolic Preaching.

This ascription to the Three of different functions in creation secures their distinction. The Father is the source of creative activity, the Son brings creation into existence, and the Spirit arranges creation into a meaningful whole: the one God who creates is three.

Out of the stormy waters of second century speculation about the nature of creation and God’s creative activity emerged Irenaeus’ theological account. The clarity with which he distinguished the Father, Son, and Holy Spirit from created beings, identified the Three as the one Creator God, and secured the distinction of the Three so surpassed his predecessors and contemporaries that Irenaeus stands alone at the end of the second century. Indeed, the ways in which Irenaeus’ successors—such as Origen and Tertullian—treat these theological categories often fall short of Irenaeus’ account. The fact that this is in large part due to the different ways in which they ascribe creative activity to the Three, further illustrates the significance of creation to Irenaeus’ theological account. It also illustrates the significance of Irenaeus’ use of creation to the history of early Christian theology. No early Christian used creation to such advantage as Irenaeus.