One of the key moments of God’s self-revelation in Scripture happens at the burning bush, when Moses asks God, “What is your name?” God answers, “I am who I am” (Exodus 3:14).

Here we see that God does not receive his name, identity, or existence from anyone or anything else. He does not depend on anything to be who he is. He simply and eternally is. It is a truth picked up many times in Scripture, for example in John’s Gospel, where we see that the Word (who again calls himself “I am,” John 8:48) does not acquire life but has “life in himself” (John 5:26).

This is why Paul can tell the Athenians, “The God who made the world and everything in it, being Lord of heaven and earth, does not live in temples made by man, nor is he served by human hands, as though he needed anything” (Acts 17:24–25). The living God isn’t in any need. He doesn’t need anything to be better, to be more God, or to be more fully himself. He depends on nothing. He has fullness of being. He has life in himself.

Theologians call this the doctrine of God’s self-existence or aseity (from the Latin a se, meaning “from/of himself”). From this characteristic of God, we will see, flows all the graciousness of the gospel.

God Needs Nothing

In this lack of need, God is utterly different from idols.

In Acts 19, in Ephesus, Demetrius the idol-maker makes a striking admission. He complains that if Paul is allowed to say that man-made gods are no gods at all, then

there is danger not only that this trade of ours may come into disrepute but also that the temple of the great goddess Artemis may be counted as nothing, and that she may even be deposed from her magnificence, she whom all Asia and the world worship. (Acts 19:27)

In other words, the divine majesty of Artemis is dependent on the service of her worshipers. For all her apparent magnificence, she needs her minions. In herself she is empty and parasitic.

“God is so overflowingly, superabundantly full of life in himself that he delighted to spread his goodness.”

In absolute contrast, God does not need the world in order to satisfy himself or to be himself. The divine majesty of God is not dependent on the world. God did not create the world because of any lack in himself. He created because he was so happily self-existent, so bursting with benevolence. God is so overflowingly, superabundantly full of life in himself that he delighted to spread his goodness.

Because of God’s blessed aseity, we can know that the very creation is a work of grace. Grace, then, is not merely his kindness to those who have sinned. Before there was sin, God brought creation into being out of grace. With the self-existent God, love is not a reaction. God’s love is creative. He gives life and being as a free gift, for his very life, being, and goodness are yeasty, spreading out that there might be more that is truly good.

Where idols need worship and service and sustenance, God needs nothing. He has life in himself — and so much so that he is brimming over. His glory is overflowing, radiant, and self-giving. Because God is self-existent and does not need us, he relates to us by sheer grace. No other god can do that.

God Needs No ‘Parts’

God’s divine simplicity is really just an extension and reinforcement of that truth that God needs nothing.

“We may be lacking and needy, but God needs nothing, and so acts with constancy and kindness.”

Divine simplicity means that, just as God does not depend on anything outside himself, so in himself he does not have any parts he depends on in order to be who he is. In other words, God does not derive his being from any quality or idea or thing that might pre-exist him. There is no feature of God that predates him.

It means that God does not “have” some thing called love or holiness or goodness, as if those were removable organs of his that you could transplant. No, God is love — he is goodness itself, truth itself, beauty itself, holiness itself. Goodness, for example, is not some external standard he tries to emulate. He is goodness. God has no parts on which he depends.

So while we talk about the different attributes of God, it is not as if holiness and righteousness and justice are different ingredients that have been mashed together to produce God. He is simple, not a compound.

Regretfully, Christians do often speak of the divine attributes that way, as if they were divine flavors that sometimes sit uncomfortably alongside each other. For example, how often have you heard Christians say, “Yes, God is loving, but he is also wrathful.” We may know what’s meant, but phrased like that it can sound as if love and wrath are different moods — so that when he’s feeling one, he’s not feeling the other. But these are not separable parts of God, as if sometimes he has love and sometimes he has wrath.

No, God is angry at evil because he loves. It is the proof of the sincerity of his love, that he truly cares. His love is not mild-mannered and limp; it is livid, potent, and committed. And therein lies our hope: through his wrath the living God shows that he is truly loving, and through his wrath he will destroy all devilry that we might enjoy him in a purified world, the home of righteousness.

God is simple. He has no such “parts.”

What About the Trinity?

Yet what of the Father, Son, and Spirit? Are they not three “parts” of God?

Crucially, no! For God has not chosen to have or co-opt three parts called Father, Son, and Spirit. God is Father, Son, and Spirit. The difference may sound petty, but it is in fact most profound.

Let me illustrate with a little thought experiment. Imagine that the Father, Son, and Spirit are just three parts, three qualities God has chosen to adopt. If that is the case, then deep down, God the Father is not Fatherly in his essential being. At some point, he simply decided to start becoming Fatherly. In which case the Father has not loved the Son for all eternity. God is not, eternally, love. The very character of God must be different from what we see in Scripture.

Yet in the New Testament, the Son can say, “Father, . . . you loved me before the foundation of the world” (John 17:24). The eternal Son, the one through whom all things were created, who is before all things (Colossians 1:15–19), who is Lord and God, was loved by the Father for all eternity. The Father, then, is eternally the Father of the eternal Son, and he finds his very identity, his Fatherhood, in loving his Son.

It is not, then, that God the Father has some deeper, secret identity and only chose at some point to be Father — as if he has a nice blob of fatherly icing on top. No, he is Father. All the way down. And for that to be true, for him to be eternally Father, he must eternally have a Son. That is who he is. That is his most fundamental identity. Thus, love is not something the Father has, merely one of his many moods. Rather, he is love. He could not not love. If he did not love, he would not be Father.

He Remains Faithful

The self-existent, simple God is the only God who is not lacking. He is the only God who is inherently loving, abundant, and inclined to be gracious.

We may be lacking and needy, but he needs nothing, and so acts with constancy and kindness. He is the same yesterday, today, and forever. It means we can turn to him with confidence — always — and with wonder at his eternal fullness and magnificence. He is, day after day, a marvelous, strong tower.

Only with this God can we know constancy of comfort and constancy of wonder-filled adoration.