The Nature of God
God named himself, and all that faith confesses of him is held in that name: he is the one who is, being itself. From this single source flows all the rest, that he is one, simple, eternal, without measure, almighty, and that he is love. We know him by it, without ever exhausting him, for he remains higher than all one can say of him.
He who is
At the burning bush, Moses asks God his name, and God answers by being: “I AM WHO I AM.” Exodus 3:14 The Hebrew words of this answer, rendered as “I am who I am”, ehyeh asher ehyeh (אֶהְיֶה אֲשֶׁר אֶהְיֶה), give the very name of God, the one who is. All creatures receive their existence from another: they began, and they could fail to be. God alone is existence in person. He holds his being from nothing and from no one; he is, fully, by himself. There lies the root of all one can say of him: he does not have life, wisdom, power as goods received, he is them. To understand that God is being itself is to hold the key to all his perfections. To this name revelation at once joins another, drawn from the same verb to be: the four Hebrew letters YHWH, the Tetragrammaton, which Jewish tradition holds so holy that it is not pronounced, replacing it in reading with the word Adonai, “the Lord”. “This is my name forever, and this is how I am to be invoked from age to age.” Exodus 3:15 The Greek translators of the Old Testament rendered “the one who is” as ho ôn (ὁ ὤν), and the whole Christian tradition recognised in it what God is in his own right: not one being among others, but, in Saint Thomas Aquinas’s phrase, subsisting Being itself, whose essence is to exist.
One God
From this it follows that there can be only one. For two gods to be two, some difference would have to set them apart: one would possess something the other lacks, otherwise nothing would distinguish them and they would be one and the same being. But he who lacks something is not the fullness of being: he is not God. There is therefore but one God, and no other beside him. “I am the first and I am the last; apart from me there is no God.” Isaiah 44:6
Without parts
Because he is being itself, God is not composed. A composite thing is made of parts that depend on one another, and what is assembled can be taken apart. God has no parts: he is not made of body and spirit, and his qualities are not added to him. In us, one becomes wise, and wisdom comes to rest upon the person; in God, nothing is added, for, as Saint Augustine says, he is what he has. His wisdom, his power, his goodness are his very being: one and the same God under various names. When we call him wise, good, just, we divide into words what in him is perfectly one. This is what is called his simplicity: all that he is, he is at once and undivided. This is not a speculation of the schools but the faith the Church professes: God is “a spiritual substance, single, absolutely simple and unchangeable”, teaches the First Vatican Council.
Eternal and immutable
The same principle wills him without change. To change is to gain what one did not have or to lose what one had; God, who is all being, has nothing to acquire and nothing to lose. In him nothing waits to become: he is all that he can be, pure act with no potency to fill. It is because there is in God nothing possible that is not already accomplished that he can neither grow nor decline. He is immutable, that is, he does not change. “For I, the Lord, do not change.” Malachi 3:6 From this immutability it follows too that he is impassible: nothing stirs him or makes him suffer from without, as we are moved by what befalls us. This is not coldness but perfection: his love is an entire act, not a passion undergone. When Scripture lends him anger or regret, it speaks in our manner of a God who, for his part, remains ever the same. He is likewise outside time. Time is the measure of change. When a thing changes, it passes from one state to another, and this passage opens a before and an after; time measures this unfolding. Without change, there is no before or after to measure, hence no time. But God never changes: there is in him neither before nor after, nothing that passes and nothing that comes. He does not live one moment after another; he possesses his whole life in a present that does not pass. This is his eternity, which Boethius defines as the whole, perfect and simultaneous possession of a life without end. “From everlasting to everlasting you are God.” Psalm 90:2
Being without limit
Being itself, God has no bounds: he possesses all the perfection of being, excluding none of it. He is infinite. Nothing limits him, so nothing contains him: he is not shut within a place, he is present in every thing, more inward to each than it is to itself, since it is he who makes it be at every instant. “Do I not fill heaven and earth? oracle of the Lord.” Jeremiah 23:24 From this fullness come his power and his knowledge. He is almighty: he can do all that can be, by his will alone. He drew the world from nothing by willing it. He made it under no necessity and gains nothing by it: full of himself, he had no need of the world. He willed it freely, out of pure overflow, to communicate his goodness and to let his glory shine in his works, as the First Vatican Council defined. “Look at heaven and earth and all that is in them, and know that God made them out of nothing, and that the human race came into being in the same way.” 2 Maccabees 7:28 Nothing stands as an exception to this power. The contradictory, a square circle, is not a thing that would resist him: the words cancel each other and name nothing that could be. And if God can neither lie nor fail, it is because lying and failing are lacks, and the fullness of being lacks nothing: “If we are unfaithful, he remains faithful, for he cannot deny himself.” 2 Timothy 2:13 He is all-knowing: he knows everything without learning anything from outside, by knowing himself as the source of all. His knowledge embraces the whole unfolding of time as well. Time began with the world: in creating beings that change, God brought forth the before and the after, and he himself remains outside this time he created. We are set at a single moment, from which the past has already slipped away and the future has not yet come to us; God, for his part, is at no moment: he sees the whole of history at once, from beginning to end, as one takes in an entire road with a glance from the top of a hill. That he sees our choices in this way does not bind them: he does not look on them beforehand, but as present, and to see a thing being done does not force it to be done. His knowledge accompanies our free acts without constraining them, as the gaze follows an action without producing it. What for us is past, what for us is still to come, all of it is present to him, like the depths of hearts: “Everything is naked and exposed to the eyes of the one to whom we must give an account.” Hebrews 4:13
Providence
Knowing all and able to do all, God governs all. Nothing escapes his guidance: he leads each thing to its end and watches over the least detail. “She reaches from one end of the world to the other with her strength, and orders all things with gentleness.” Wisdom 8:1 Down to the sparrow that falls, nothing is too small for his care: “Not a single one falls to the ground without your Father willing it.” Matthew 10:29 This is what is called his providence: not a blind fate, but a Father who leads history, and each of us, toward the good. This governance does not suppress the action of creatures: God leads each thing through the causes he has made, giving fire to burn and man to act and to choose freely, so that what he does alone he does also through them. Even the evil the creature does does not escape him: he never wills it, he permits it, and from it he draws a greater good than its absence would have given, as from the betrayal that handed Joseph over. “You meant to do me harm; but God turned it into good.” Genesis 50:20
Higher than all one says of him
All this language reaches God without ever circumscribing him. God is pure spirit, without body or figure. “God is spirit, and those who worship him must worship him in spirit and truth.” John 4:24 Our words come from created things, and God surpasses them all; we name him after his works, as one guesses the author from the work, knowing that he is all this in an infinitely higher way. “Ever since the creation of the world his invisible perfections, his eternal power and his divinity, have been perceived by the mind through the things he has made.” Romans 1:20 This is why one often knows better what he is not than what he is, and every word about him falls short. “Do you claim to fathom the depths of God, to reach the limit of the Almighty?” Job 11:7
This is what is called speaking of God by analogy: the words keep a true sense, but a transposed one, for between the Creator and the creature the likeness is always less than the difference, as the Fourth Council of the Lateran, in 1215, taught. One advances thus by three steps, along the path the Fathers traced in the wake of Denys the Areopagite: to affirm of God every perfection (he is good, wise, living), to deny in him the limit that affects it in us, then to attribute it to him in a supereminent way. “As high as the heavens are above the earth, so far do my ways surpass yours, and my thoughts your thoughts.” Isaiah 55:9
Holy, good, love
This fullness of being is fullness of good. God is goodness itself, of which every other good is but a reflection, and the holy one above all, set apart from all evil, before whom the angels veil themselves. “Holy, holy, holy is the Lord of hosts! The whole earth is filled with his glory.” Isaiah 6:3 This good does not keep itself for itself, it gives itself: God created out of pure generosity and communicates himself without end. This good is also justice: God renders to each according to the truth, and no wrong is found in him. “He is the Rock: his work is perfect, all his ways are just; he is a faithful God, without injustice; he is righteous and upright.” Deuteronomy 32:4 But his justice does not war against his goodness, for his way of doing justice is to show mercy: slow to punish, quick to forgive, he bends over misery to raise it up. When he proclaims his name to Moses, this is how he names himself: “The Lord, the Lord, a God of tenderness and compassion, slow to anger, rich in faithful love and faithfulness.” Exodus 34:6 In God, justice and mercy do not quarrel: they are one single love, which wills the good and raises up the one who had lost it. At the last, all this fullness receives a name. “God is love.” 1 John 4:8 All the perfections we have named, unity, simplicity, eternity, power, find there their face: being itself is a love that gives itself.
God has revealed that this being is an exchange of love: the Father, the Son and the Spirit, one God in three Persons. The nature of God is this inexhaustible fullness, which the blessed will contemplate in eternal life without ever exhausting it.