One of the gifts from the East comes from what we in Western Christendom call Eastern Orthodoxy. For centuries, Orthodoxy (as its adherents speak of it) lost contact with the West. During the Middle Ages, the Byzantine Empire and lands to the east where Orthodoxy had taken deep historical root were overrun, overwhelmed and repressed by Muslim forces, culminating in the half millennial dominance of the Ottoman Empire. While Orthodoxy survived in and had profound influence on what would become the Russian State, dominance by czars and suspicion of western Europe kept Orthodoxy there isolated. Since the beginning of the 20th century, with the collapse of the Ottoman Empire and the exodus of many Orthodox faithful from Communist repression in Russia, Orthodoxy has reintroduced itself to the West. Over the past century, Christians in western Europe and North America have been getting reacquainted with our Eastern brothers and sisters. They have brought us a profound gift, one we in Western Christendom originally shared with them but mislaid. That gift is the welcome of the Divine Mystery – of who God is and what God does.

The early Church was marked by a remarkable commonality of teaching wherever one travelled. This became a main argument for Irenaeus in the 180s in his magnum opus Against Heresies: Indeed, he staked the genuineness of the Church on its faithfulness in maintaining the apostolic tradition, in its unity, back through the generations to the apostles themselves. While it has become de rigueur in some patristic scholarship to emphasize instead the allegedly wide diversity within early Christianity, such allegations run aground on the shoals of what is found in early Christian writings if understood in context and with a modicum of sympathy for the challenges of conversing in different languages. This commonality of teaching continued to be prized by the Church through subsequent centuries, as against the heresies that arose and were condemned by ancient ecumenical councils.

Recognizing this is the necessary backdrop for appreciating the ancient Church’s universal recognition that in speaking of God and his works we are encroaching on what cannot be explained by human reason, even as aided by Scripture: God and His works are beyond our comprehension. We can (and must) proclaim His wondrous works; we can (and must) declare His greatness; we can (and must) instruct others and receive instruction ourselves in what He has revealed and how He wants us to respond. But in speaking of God as God, in talking about what He does to bring salvation to us, we are treading on holy ground – the ground of mystery. Here, like Moses, we must take off our shoes; here, the ancient Church affirmed, we must loosen the sandals of our reason and kneel in wonder. For the faithful of Christian antiquity, Divine Mystery was not a lurking, dangerous threat that had to be analyzed and reduced to manageable terms: it was the unfathomable love of the One who is also Three, from whose saving love nothing can ever separate us, a love that works within us beyond our understanding to make us His own.

No matter where one turns in the patristic witness, this is the constant pattern: One encounters it in Irenaeus, Tertullian, Hippolytus, Minucius Felix, Origen, Athanasius, Pseudo-Macarius, Cyril of Jerusalem, Basil of Caesarea, Gregory Nazianzen, Gregory of Nyssa, John Chrysostom, Cyril of Alexandria, Hilary of Poitiers, Maximus the Confessor, and John of Damascus. The Church fathers sang the same song: God is a wondrous mystery, and His works toward us cannot be fathomed. These stalwarts used their reason, of course, to expound Scripture and proclaim the Christian message: They sought to present it in ways accessible to the cultures in which they laboured. But when it came to “figuring out” God, to “understanding” God as God, to “explaining” how God could be both One and Three and how Jesus Christ could be only one person while both fully divine and fully human, the Church fathers universally and constantly rejected what human reason could make of those paradoxes. Indeed, all the heresies condemned by the ancient ecumenical councils – Arianism, Apollinarism, Nestorianism, Eutychianism, monophysitism, monothelitism – used human reason to figure out one or the other of those imponderables. And the doctrinal deliverances of the ecumenical councils – the Nicene Creed of 325, the Nicene-Constantinopolitan Creed of 381, and the Council of Chalcedon’s Definition of the Faith in 451 – never tried to explain the doctrine they universally confessed. Those creeds were not doctrinal maps for exploring the Divine Being: they were no trespassing signs warning against intellectual or doctrinal transgression.

In the same vein, the Church fathers also rejected any attempt by human reason, even with the best of intentions, to comprehend how God works salvation within us. That God works through grace, faith, love and sacrament to bring us to Himself is the constant, unmistakable theme of patristic proclamation – faithful to the apostolic tradition. But endeavouring to explain precisely how He does all this is something they refused to do.

For our purposes, within this common patristic stance, two emphases step to the fore: the incomparability of the Divine Being as Three-in-One and the unfathomability of how God’s grace works within us. According to the Church fathers, even sanctified human reason cannot plumb these depths. Some have tried – with dire results.

Arius, Eunomius and others attempted to comprehend the Divine Being by comparing it with human beings (made in God’s image). For this, they were condemned by ecumenical councils and the united chorus of the Church fathers: It was recognized that such explanations or comparisons not only reduced God to an exalted form of something created but that each also made the salvation achieved by Jesus Christ and proclaimed in the apostolic tradition impossible. All the ancient creeds adopted by the ecumenical councils included the phrase “who for us and for our salvation” at the heart of its confession, recognizing that the apostolic tradition proclaimed this faithfully but that the opposed teaching undermined it. The wonder of who God is as God and of how He works within us to save us beggar explanation but call forth praise. For the Church fathers, these are mysteries – not to be solved but to be celebrated.

This was the pattern throughout ancient Christianity. It has remained the pattern within Orthodoxy. It was the pattern we in Western Christianity shared in antiquity – but one we have long since departed from.

This can be seen in a startling comparison. Within worldwide Orthodoxy, from antiquity to the present day, there are no differences in doctrine and there have been no Church divisions. Owing to the way Orthodoxy organized itself (by the respective nations that converted to the faith), there are distinct Orthodox churches – Greek, Serbian, Bulgarian, Russian etc. But these are distinct only as national or ethnic ecclesiastical bodies; they are not divided by doctrinal differences. By striking contrast, differences in doctrine mark the path of Western Christianity, and these have led to division after division – so much so that, by the most conservative numerical reckoning, Western Christianity at the beginning of the 21st century had more than 26,000 denominations. How did this come to pass? What happened to shift things so dramatically in Western Christianity? We in Western Christendom got off track in the matter of our confidence in (sanctified) human reason centuries ago – and the chickens have come home to roost.

Some readers may already have noticed one striking omission from the list of Church fathers above who stood resolutely opposed to any and all attempts to fathom the mysteries of God and His work in us. This is a significant omission, indeed, since that one is the Church father who has had the widest and deepest influence on Western Christianity; he is also the Church father Orthodoxy views with hesitation, even suspicion: Augustine of Hippo. There are solid reasons why Orthodoxy has cautions about Augustine; and it is undeniable that Western Christianity has been profoundly moulded by the ancient Bishop of Hippo. Fundamental to both of these is his confidence in human reason to fathom the mysteries of who God is and how He works in us.

It might seem churlish to raise questions about someone of Augustine's undeniable standing and influence. He was the patristic North Star for the navigations of medieval scholarship in Western Christianity; during the Reformation era, as Roman Catholics and Protestants sought to bolster their arguments by appeal to patristic testimony, the Church father most cited by both was Augustine. He has profoundly influenced the development of Western Christian thought from his lifetime onward; there hardly seems to be a major question that has arisen in Western Christian teaching that was not anticipated by something he wrote.

Augustine was unquestionably a genius. He was the most gifted philosopher ever produced in the Latin world of his day. The City of God was a masterpiece of extended reflection on the course of history, one that far exceeded in depth and scope anything produced by any other Church father on a related topic. His Confessions offered a kind of literature hitherto unknown within the ancient Church – and it has wielded enormous influence on Western Christian teaching and spiritual practice. The massive scope of his exegetical and doctrinal writings, the vast extent of his letters, his engagement in various doctrinal controversies, plus his episcopal leadership of Hippo (with all the day-to-day responsibilities that entailed) together demonstrate that he was extraordinarily talented, hard-working and persistent in pursuing what he understood to be right and necessary.

Even so, he had his limitations. As with many other Church fathers, he never learned Hebrew, the language of the Old Testament. More significantly, he never became fluent in the sophisticated Greek used by the Church fathers in the eastern half of the Church. As a teacher of rhetoric, he had mastered skills of articulating his thoughts winsomely and convincingly, but his skills in this regard were limited to Latin – in which he taught and wrote prodigiously, to be sure. But one looks almost in vain for evidence that he had imbibed the attitudes, perspectives and instincts of the Greek Church fathers who preceded him or were his contemporaries. That is telling when one considers how this incredibly gifted thinker responded to the mysteries of God and His work in us. While Augustine dutifully acknowledged our human limitations for plumbing these mysteries to their depths, he nonetheless opined that they could be deciphered to some degree – something he attempted. Augustine had great confidence in sanctified human reason to explore realms of mystery where his patristic predecessors had refused to try to go. We will point to two of these, for which Augustine is well-known. His confidence in human reason to explain divine mysteries infected subsequent Western Christian perspectives.

In his heavy tome, On the Trinity, Augustine set out not only to present this Christian teaching for his readers, he also was determined to find some analogy in creation for the Christian confession that God in his Being is Three in One. It is striking that he so vigorously attempted, time and again in this extended work, to do precisely what his patristic predecessors adamantly asserted could not possibly be done and should not even be attempted. Even if I do not list the many Church fathers who more generally urged that the Divine Being was beyond our ken (virtually every one of them), the list of those who explicitly rejected any attempt to find an analogy in creation to the Triune God in his Being included Hippolytus, Basil of Caesarea, Gregory Nazianzen, Gregory of Nyssa, John Chrysostom, Cyril of Alexandria and Hilary of Poitiers. The analogy Augustine eventually settled on – the assessment of the human mind's memory, understanding and will – is inadequate to the task, as Augustine himself acknowledged. But he expressed hope that others would continue the quest.

Furthermore, Augustine turned his prodigious intellect to exploring how grace, human will and divine predestination relate. He was the first Church father to take on this task. It was not as if none before him had perceived that these all factored into how salvation gets applied and received. The Hellenistic culture that had permeated the eastern half of the Roman Empire, where the Greek Church fathers all laboured and flourished, had long recognized and wondered about the intersection of human freedom and fate, of coincidence and determinism, of life and death: these were staples of the Greek playwrights, whose works had so significantly shaped their intellectual and cultural world. But those Greek Church fathers had resolutely avoided going beyond the obvious recognition that a God beyond time would not be surprised by what transpired in the world he had made and controlled, that salvation is entirely of divine grace and that one must choose to respond with faith to the proclamation of divine salvation. To try to analyze how grace, free will and divine sovereignty interact, though, was something they did not attempt – not because they might not have been up to the mental challenge (we are talking here about intellectual heavyweights such as Gregory Nazianzen and Gregory of Nyssa, after all), but because how these relate are divine mysteries that are and must remain beyond human comprehension.

But Augustine – for a variety of reasons, especially the preposterous teachings of Pelagius – nonetheless sought to analyze them. One might argue that Augustine had been forced by circumstances to pursue these questions, but then one should recall that Pelagius’ teachings, once they became known in Eastern Christendom, were repudiated as heresy, without anyone there attempting to explain how those issues should be understood and interrelated.

It is not the place here to explore what Augustine taught on this topic. Suffice it to note, though, that Augustine had attempted to explain how predestination, human will and grace work to bring salvation to its recipients. In so doing, the Bishop of Hippo manifested his confidence in sanctified human reason – his own, to be sure, as gifted a theologian as he unquestionably was – to pronounce on this mystery. As subsequent Western Christian history has shown repeatedly, from Prosper of Aquitaine through Gottschalk through the Reformation era down to our own day, many have tried to follow in Augustine’s footsteps. Roman Catholicism has seen this with the Jansenist movement; Protestants joined the fray on both the Lutheran and the Reformed sides (with the latter becoming especially noted for their commitment to this tangle of issues). And the eager readiness of young would-be theologians to dive into this conundrum and pronounce upon it indicates that Augustine opened a Pandora’s box when he determined to explain this mystery.

The confidence Augustine thus demonstrated in sanctified human reason quickly became the hallmark of Western Christian thought. Within a century of his death in 430, the Council of Orange (529) adopted an explanation of baptism. In the 800s, the monks Radbertus and Ratramnus engaged in a dreary argument attempting to explain how the Lord’s Supper works (how the bread and wine become the body and blood of Christ), an argument ostensibly settled by the Fourth Lateran Council (1215), which appropriated Aristotelian terms (form and substance) to explain how the bread could become the body of Christ and the wine, his blood while still looking and tasting like bread and wine. In due course, these explanations seemed inadequate, and the late Middle Ages and the Reformation era heard further solutions to understanding the sacraments of Baptism and the Eucharist.

In due course, Protestant movements splintered over different explanations of the sacraments, and conflicting explanations helped spawn rival Church bodies. The pattern has not limited itself, of course, to sacraments only: Doctrines of all kinds became battlegrounds on which combatants of various stripes contended, seeking to proclaim “the truth, the whole truth, and nothing but the truth” with their contradictory assertions. By now, this habitual pattern has devolved into the 26,000 denominations – all separated from the others by competing explanations of the mysteries of God's work within us and the ramifications that those explanations entail. This pattern was unknown in Christian antiquity until Augustine.

In the meanwhile, Orthodoxy has stood firm with the Church fathers in refusing to attempt to solve the mysteries of God and how God works within us for our salvation. The Church fathers prior to and after Augustine resolutely decried any attempt to explain Baptism or the Lord's Supper: indeed, to this day, the term used in Orthodoxy for the two sacraments is the mysteries. Orthodoxy, adhering to the united patristic witness and following the pattern set forth in Christian antiquity down to the present day, has never attempted to understand the mysteries of God in His Being or of how God works salvation in us. Within Orthodoxy, these mysteries are to be celebrated, not solved.

Augustine has had prodigious influence within Western Christianity in a host of ways, many of which we must praise God for; however, Augustine has also introduced something into Western Christianity that has had dire consequences. There is no hope or expectation with this article that we could somehow “turn back the historical-theological clock” and inoculate Western Christianity against its Augustine-influenced propensity to plunge into explanations where, if not angels, then at least the rest of the Church fathers feared to tread. But perhaps we can listen to our Eastern siblings enough to recognize the privilege of celebrating divine mysteries instead of trying to solve them. And with that, perhaps, we can learn to embrace fellow Christians in the West whose explanations may not satisfy us but who, with us and our Orthodox brothers and sisters, delight to acknowledge the unfathomable love of God toward humanity. This, surely, would be a gift from the East that we can treasure.