Au contraire! John of Damascus, Maximus the Confessor et al. countered the persistence of the dualists into their own time; indeed, as they stood as Christian theologians of the East in the 7th and 8th centuries. For Augustine, in his pagan days, he partook of an early dualistic religion, known as Manicheanism. This type of dualism, indeed, as it was imbibed by the Gnostics, and even some so-called Christian Gnostics, gained a foothold into the life of the Church, the world, that would perdure even into our present in the 21st century. For the Confessor and the Damascene, they were fighting some heir-apparents of the earlier formed Manicheanism and Gnosticism simpliciter. In their day, respectively, these folks were identified as the Paulicians, and latterly (after Maximus and John), the Bogomils. In nuce, these dualistic systems attempted to identify two competing principles within the world, within the principle of all reality; such that, when applied to God, they saw Light versus Darkness as two equidistant primordial combatants. As a result, they posited two principles largess, rather than just the one that Christian trinitarian monotheism thought from. Even so, these heretical dualistic groups had enough purchase among the people, that people like Maximus, in his respective time, and John of Damascus in his, felt the need to counter them through Christian and biblical theological reasoning (which also entailed some metaphysics).
Jaroslav Pelikan describes the competition this way:
While maintaining against Judaism that the Shema did not preclude the doctrine of the Trinity, but rather, when correctly understood, included it, orthodox Christian monotheism simultaneously opposed any effort to modify the singleness of the divine nature through the introduction of a double principle [ἀρχή]. The Trinity did not imply any compromise in the fundamental axiom that the divine principle was one, and in opposition to the Filioque this axiom was reinforced. To the dualists the orthodox declared: “For our part, we do not follow your godless ways, nor do we say that there are two principles which are to be separated according to location. But, declaring that there is one Creator of all things and a single principle of all things, we affirm the dogma . . . of the Father and the Son.” “The confession of two principles, an evil god and a good one” was understood by the orthodox to be the “first article” of the Paulician creed, taken over from the Manicheans. From the Manicheans and Paulicians the notion of a multiple principle had in turn been taken over by later dualist groups, particularly the Bogomils. Biblical justification for it was found in such passages as Matthew 7:18, which said that there were two different sources for the two different kinds of deeds, or 2 Corinthians 4:3–4, which spoke of “the god of this world.” Replying to such exegesis, the orthodox produced biblical evidence that the very rejection of the authority of God by the world was evidence for one principle rather than two; for Christ “came to his own home, and his own people received him not.”
Although in later theologians the proof from Scripture took a more prominent role, in the polemics of John of Damascus such proof was heavily reinforced by logic and metaphysics. When the Manicheans contended that the two principles “have absolutely nothing in common,” he replied that if they both existed, they had to have at least existence in common. By their very use of the term “principle,” the Manicheans contradicted their own dualism, for a principle had to be single. As in mathematics the unit was the principle of every number, so it was in metaphysics. If there was an individual principle for each existing thing, then these many principles had in turn to have a single principle behind them. Otherwise there would not be only the two principles of God and matter, as the dualists taught, but a plurality of them throughout the universe. Not only was this an absurdity on the face of it, but it negated the meaning of the word “principle.” Good and evil were not to be explained on the basis of a dual principle, but rather “the good is both the principle and the goal of all things, even of those things that are evil.”[1]
Okay, that is all well and interesting. But what I want to do with this is to attempt to identify how this type of dualism is presently present within the 21st century world, whether that be in the sacred or secular.
My simple observation is this (and this is for Christian consumption, primarily): The devil himself loves nothing more than leading people into the delusion that in fact he is equiprimordial with the living and triune God. He likes to lead his kingdom of darkness, and even us Christians who are still, in principle, in it (but not of it), into the fantasy that his powers of darkness represent a real-life contradiction of God’s life and Light. It is easy, in our bodies of death as we are, to give into this satanic delusion; indeed, even as Christians. In this current world of chaos and disorder it might in fact appear that the devil and minions have an upper hand on God’s economy in the world in Jesus Christ. But just as the Paulicians and Bogomils logic of antiChrist proportions were defeated, indeed, imploded, by folks like Maximus and John of Damascus, in their own respective ways, that same theo-logic applies against the inherent dualisms of our day in the 21st century.
Hence, there is no absolute dualism between the living God, and the minions of darkness. As the Apostle Paul triumphantly declares: “When you were dead in your transgressions and the uncircumcision of your flesh, He made you alive together with Him, having forgiven us all our transgressions, having canceled out the certificate of debt consisting of decrees against us, which was hostile to us; and He has taken it out of the way, having nailed it to the cross. When He had disarmed the rulers and authorities, He made a public display of them, having triumphed over them through Him” (Colossians 2:13–15). Jesus as the Theanthropos came and destroyed, not an abstract evil, but a concrete one as that has polluted the human being, from the inside/out. Even though evil and sin remain consequential things in this ‘evil age,’ they eschatologically have already been put to death by the Godman, Jesus Christ. He currently is reigning at the Right Hand of the Father, which so contraposes the so called god of darkness, that the apparent war can be said to have never even really gotten off of the ground for the satanic horde’s parasitic “nothingness” economy.
And so, our Lord, contra the dualistic-delusion exhorts: “These things I have spoken to you, so that in Me you may have peace. In the world you have tribulation, but take courage; I have overcome the world (John 16:33).” He has not left us as orphans, or as defeated ones. What can death do to us? The same thing it did to Jesus. Though we die, yet shall we live. The forces of this current world order have been defeated; death has been put to death; the scourge of sin has lost its power; and we in fact are the victorious ones as we stand in the Victor of God’s grace for the world in Jesus Christ. This doesn’t necessarily make our daily lives easier, per se, but it does let us know that even though we might feel like we are drowning in the scuz of this world system, even within our own bodies of death, we know as Christians that the power of God, the Gospel funds our lives in Christ by the Holy Spirit, to the point that we can stand in victory. Even if such victory, to the dark-system, looks like defeat (like weakness and foolishness).
Dualism is a wicked evil in our world. Most Westerners are caught in its clutches by their submission to New Age theatrics and demonism (this is ironic because New Ageism is based broadly in Eastern monism—I need to flesh this out more fully since New Age ostensibly denies dualisms::I don’t think they actually achieve that though). But as we have already visited, these types of dualistic movements have been present throughout the world order since at least Genesis 3. And yet, even before these fake-power-plays came into existence in the natural world order, God had already pre-destined Himself to be for the world, to not be God without, but with us in Jesus Christ. The Enemy, the darkness has never had an eschatological chance in hell to get beyond the boundary of hell God had always already determined for it in His free life as the Deus incarnandus (the God to be incarnate).
[1] Jaroslav Pelikan, The Christian Tradition: A History of the Development of Doctrine: The Spirit of Eastern Christendom (600—1700), Volume 2 (Chicago and London: The University of Chicago Press, 1977), 219–20.