Here is how the early Church Fathers and theologians described the nature of God:
Tatian the Syrian
“Our God knows no beginning within time. He is Himself without origin, acting as the very fountainhead of all existence. God is spirit, existing entirely apart from matter; rather, He is the architect of the material spirits and the phenomena that manifest within the physical realm. He is the invisible Father of both the perceptible and the unseen” (Epistle to the Greeks 4 [A.D. 170]).
Athanasius
“I have demonstrated sufficiently that we are not atheists, for we acknowledge one God—unbegotten, eternal, invisible, unchanging, incomprehensible, and unbound. He is a being known only through intellect and reason, enveloped in light and beauty; He is spirit possessing indescribable power, through whom all things were created and ordered by His Word, and through whom they are sustained in being” (Apology for Christians 10 [A.D. 177]).
Irenaeus
“The Father of all things remains far removed from these earthly affairs, from the fleeting emotions and passions of men. He is simple, lacking any composition or structure, being identical only to Himself. He is pure intellect, pure spirit, pure thought, and pure reason... the very essence of light and the ultimate source of every good; this is how the pious and religious have always spoken of God” (Against Heresies 2,13,3 [A.D. 189]).
Clement of Alexandria
“Consider the hierarchy of substance: first, there is that which exists purely in itself, much like a stone is defined as a substance. Second is the substance capable of growth, such as a plant that flourishes and then decays. Third is the animated, sensory substance, like an animal or a horse. Fourth is the animated, sensory, and rational substance, found in mankind. From this, we see that each of us is composed of elements of the whole, for we possess an immaterial soul and mind, which serves as the image of God” (Excerpt from On Providence [A.D. 200]).
“Being resides in God. God is the divine Being, eternal and without beginning, incorporeal and limitless, the cause of everything that exists. To be is to persist completely. Nature is the truth of things, their inner reality. For some, nature is merely the product of what has come to be; for others, it is God’s providence, which causes being and provides the mode of existence for all created things.” (Ibid).
“What is God? ‘God,’ as the Lord says, ‘is spirit.’ Spirit is a specific, incorporeal, and indescribable substance. Incorporeal means that which possesses no body, whose existence is not defined by breath, length, or depth. And indescribable refers to that which occupies no space, yet dwells fully within all things, and within each thing entirely, while remaining perfectly itself.” (Ibid).
“No one can truly express Him in His entirety. Because of His sheer magnitude, He is defined as All, and He is the Father of all creation. There are no parts to which He could be assigned, for He is One and indivisible; thus, He is also infinite. We do not speak of Him in terms of being incomprehensible, but rather in terms of His sovereign, dimensionless, and boundless nature. Therefore, He is without form or name (Miscellaneous 5,13 [A.D. 208]).
Origen
“Since our own minds are inherently incapable of perceiving God as He truly is, we recognize the Father of all creation through the beauty of His works and the elegance of His handiwork. Thus, God is not regarded as a bodily being or one who inhabits a body, but as a purely intellectual Being, acknowledging that there is no addition or composition of any kind within Him” (Fundamental Truths 1,1,16 [A.D. 225]).
“John writes in the Gospel: 'No one has ever seen God,' clearly stating to all who have understanding that there is no nature through which God is visible—not because He might accidentally be seen by the eyes of a perishable creature, but because it is impossible by His very nature to be seen” (Ibid 1,1,8).
Athanasius
“God, however, since He has no parts, is the Father of the Son without division or change. For there is no beginning derived from His incorporeality, nor does anything enter into Him as it does into man. Simple in His nature, He is the Father of the only Son” (Letter on the Council of Nicaea 11 [A.D. 350]).
I suppose I should start by saying that there are times when one feels a bit lost in the shuffle of things, much like wandering through a dense fog without a compass, though perhaps even more aimlessly than that. It’s an odd sensation, isn't it? To feel as though you are drifting through life without a clear sense of direction or purpose, almost as if the very ground beneath your feet were made of shifting sand rather than something solid and dependable. There was this one afternoon, years ago, while I was sitting in a quiet little café over in Seattle—just watching the rain hit the window and thinking about how unpredictable existence can be—that I realized just how often we find ourselves stumbling blindly through our own decisions. We try to make sense of everything, to build these elaborate structures of logic and reason, yet we often end up feeling quite sightless in the face of true uncertainty. It’s a heavy thought, certainly, but one that seems to weigh on many of us as we navigate the complexities of being alive in this great, sprawling nation.
"God is simple, uncomplicated, and purely spiritual in nature; He possesses neither ears nor any physical organs for speech. He is pure essence and infinite, existing without being composed of numbers or constituent parts" (Holy Spirit 35 [a.d. 362.]).
Hilary of Poitiers
One must first hold fast to the realization that God is entirely incorporeal. He isn’t some collection of physical parts or a composite of various limbs and organs that might make up a biological body. If we look at the Gospel, it is clearly stated that God is spirit—invisible, eternal in nature, immeasurable, and completely self-sufficient. It is written that a spirit lacks the flesh and bone that define our physical existence; God’s very substance requires none of those earthly components. Yet, even though He lacks a physical frame, He remains omnipresent, dwelling within all things—all-hearing, all-seeing, all-acting, and the ultimate sustainer of everything in existence.
Basil the Great
“God’s actions may manifest in a thousand different ways, yet His essence remains beautifully simple” (Letters 234,1 [A.D. 367]).
Ambrose Milanski
God is essentially simple in nature; He isn't composed of parts, nor is He a collection of different elements. You can't really add anything to Him to make Him "more" than what He is. In His very essence, He possesses only that which is divine—it is the quality that fills everything entirely. He doesn't mingle with or get entangled in anything else, yet at the same time, He permeates all things. While He flows through everything, nothing can ever penetrate or intrude upon Him. It is a bit like how light might fill a room without being changed by the objects it touches, except much more profound. He remains perfectly complete and present everywhere all at once, whether we are looking up at the heavens, walking the streets of a city like Chicago, or staring out at the most remote reaches of the Atlantic Ocean. To the human eye, His true nature remains utterly beyond our ability to fully grasp or communicate.
Evagrius Ponticus
To those who point a finger at us and claim we are teaching a doctrine of three separate gods, let them understand that we confess only one God—not in terms of quantity, but in essence. You see, when we speak of something being numerically one, that doesn't necessarily mean it is absolutely singular or simple in its very nature. It is a concept widely accepted by scholars and theologians alike: that God is simple and not composed of various parts.
Gregory Jackson
There will never be—nor could there ever be—any dogma within the Church of God that would attempt to prove that the simple, indivisible nature of God is anything other than what it truly is. To suggest that He is multifaceted, shifting, or somehow composed of conflicting elements is simply a fallacy. The sheer simplicity found within the dogma of truth serves only to reveal the true essence of God exactly as He is.
John Chrysostom
When we look at how Paul approaches his understanding of God, he isn't suggesting that he possesses a fragmented view of the Divine essence—as if he were holding one piece of a puzzle while lacking the rest. That wouldn't make much sense because God is fundamentally simple, a singular and undivided reality. Rather, when he uses the term "partially," he’s really just acknowledging the vast, unbridgeable gap between human perception and the actual nature of the Creator. He knows, with absolute certainty, that God exists; he recognizes the presence of the Divine in the world around him. But as for what God truly is in His essential being? That remains a mystery beyond the reach of our limited intellect. It is less about knowing only a fraction of the truth and more about recognizing that the full magnitude of God's essence is simply too immense for us to ever fully grasp.
Why does John insist that "no one has ever seen God" (John 1:18)? I suspect he’s making a distinction regarding our capacity for true, perfect comprehension—that deep, intimate knowledge of the Divine essence. If you look at the various instances in history where people claim to have had visions of God, you'll notice a pattern of inconsistency. It’s almost self-evident that none of those individuals actually caught a glimpse of the pure, unadulterated essence of God, because if they had, their experiences wouldn't be so wildly different from one another. You see, God is fundamentally simple, undivided, and without any physical shape or composition; yet, the visions people report are all varying shapes and forms.
Augustin
When we look at the world around us—this swirling, ever-changing landscape of physical things—we have to make a distinction between what a thing actually is and how it simply appears to be in a given moment. In these shifting, created realities, if we aren't describing the core essence of a thing, we are merely talking about its accidents—those fleeting qualities like color, shape, or position that drift and change as time passes. It’s much like how a car might be red one day and blue the next after a repaint, or how a house might feel warm in the afternoon and cold by midnight; the "redness" or the "warmth" isn't the house itself, but just a temporary state of being. However, when we turn our gaze toward God, the entire framework shifts. There is absolutely nothing in Him that can be categorized as an accident. You won't find any fluctuations or passing whims there, because there is no change within the Divine. Everything we can possibly say about Him doesn't just describe a temporary quality or a passing mood; rather, everything spoken of Him pertains directly to His very substance. He is constant, unchanging, and entirely whole in Himself.
Cyril of Alexandria
By our very nature, we aren't exactly simple creatures; yet, the divine nature—which is perfectly simple and lacks nothing by design—holds within itself an absolute abundance of all perfections and requires nothing more from the outside world.
"The very essence of the supreme God, being inherently simple and indivisible, can never be split into two parts" (The Riches of the Holy Trinity 11 [a.d. 424]).
When you encounter Divine Scripture speaking of God through the lens of physical actions or bodily descriptions, try not to let your mind get bogged down in those literal, tangible details. It is so easy to fall into the trap of visualizing the material world when we read such passages, but I find it much more fruitful to look past the physical imagery used as a metaphor and instead step into the profound beauty of the underlying concepts. Rather than fixating on shapes, quantities, specific descriptions, or any other physical attributes that define our earthly existence, one should strive to contemplate God—even though He remains far beyond the grasp of our limited intellect. We simply cannot speak of Him in truly human terms; after all, there is no other way for us to conceptualize things that so vastly transcend our own understanding.