Christians worship the true God, whose proper name is “I am” (Ex. 3:14). Some may perhaps regard this as a weightless and impoverished name for God. After all, can we not say “it is” about everything that is real, from elephants to electrons? How, then, is the name “I am” a peculiar and meaningful name for the God we worship and upon whom we depend for life, breath, and all things (Acts 17:25)? The context of God’s remarkable self-disclosure of His name to Moses in Exodus 3 is His promise to deliver Israel from its bondage in Egypt. Moses confesses his own self-insufficiency for this redemptive work (Ex. 3:11). To assure Moses and the children of Israel that He is perfectly sufficient for this almost unimaginable salvation, God identifies Himself with this unusual moniker. This name indicates the reason for God’s perfect reliability.
Theologians have long understood this name to signal God’s unqualified self-sufficiency and boundless plenitude of being. God does not say to Moses “I am this” or “I am that” but simply “I am who I am.” He does not specify or contract His act of being to anything in particular, thus divulging to us the incomprehensible truth that He simply is His own is, His own reason for being. This is precisely why we can depend on Him utterly and unreservedly—because He does not depend on anything, not even an act of existence, that is really distinct from Himself. If God were in any way a dependent being, all our confidence in Him would have to be grounded in something more fundamental in reality than God. Yet Holy Scripture is abundantly clear that there is nothing more basic and absolute in being than God. He is the One from whom, through whom, and to whom are all things (Rom. 11:36). We can trace out the causal explanation for all nondivine beings and events ultimately to God Himself. And if we ask, “Why God?” the answer is simply “God.” As “I am,” God just is the is by virtue of which He exists. Properly speaking, God does not “have” existence but rather “is” existence itself subsisting, as has been affirmed by orthodox Christian theologians across the centuries. His existence contains within it all the reality that we ascribe to Him—His wisdom, power, goodness, justice, love, truth, and so on. God’s is should be thought of as the infinite fullness of being and not as the stripped-down notion of merely “being there.”
The nickname given to this doctrine of God’s independent self-sufficiency is aseity. This is adapted from the Latin a se, which means “from himself” or “of himself.” Perhaps it would be helpful to think of this as the doctrine of God’s of-Himself-ness. The Dutch Reformed theologian Herman Bavinck says that “when God ascribes this aseity to himself in Scripture, he makes himself known as absolute being, as the one who is in an absolute sense.” Bavinck adds, “By this perfection he is at once essentially and absolutely distinct from all creatures.” Creatures, just because they are creatures, depend on causes of their being in order to exist, to possess the particular natures they do, to operate as they do, and so forth. But God does not exist or operate with any such reliance on causes. He gives to all but receives from none. As God asks Job in Job 41:11: “Who has first given to me, that I should repay him? Whatever is under the whole heaven is mine.”