The Unchanging God
Anselm famously stated that God is "that being of which there is none greater." The members of the Westminster Assembly explained that God is "a Spirit, infinite, eternal, and unchangeable in His being, wisdom, power, holiness, justice, goodness and truth." The living and true God is an infinite and eternal being. He is also a personal and communicative being. The Triune God reveals Himself and His will to His creatures in His word so that they might truly know Him in Christ (John 17:3). All that God has revealed about Himself in Scripture, He has revealed in human language. He reveals Himself and His ways to us by means of "anthropomorphic" terms (i.e. human forms) and "anthropopathic" terms (i.e. human emotions) so that we can understand. This makes our limited understanding of the incomprehensible God really possible. However, it also requires us to make sharp distinctions based on literary forms and systematic theological categories. Such is the case in the language of God.
When we consider the anthropomorphic and anthropopathic language of Scripture we must be clear that these are simply accommodations. God does not and cannot change. No change in God is brought about by things outside of Him. God is not caught off guard by the actions of His creatures. God does not learn anything from His creatures. Rather, God has--as the Westminster Confession of Faith states--"foreordained whatsoever comes to pass." God stands outside of time, even as He works His eternal plans out in time and space. The immutability (i.e. unchangeableness) of God gives believers the strongest consolation that nothing will keep Him from fulfilling His promises (Mal. 3:6; Heb. 6:17–18).
Nevertheless, God is personally involved in all of His creation in accord with His own character and attributes. Believers commune with the living God in prayer and worship. God disciplines us out of His love for us (Heb. 12:3–11). God indwells and empowers believers by His Spirit--causing Christ to be formed in us (Eph. 3:17; Col. 1:27; Gal. 4:19). The Lord intervenes in our lives to bring about His will (Heb. 13:21). We can do things that anger God, and we can do things that please Him (Mic. 7:18; 2 Cor. 5:9).
So how are we to explain the intersection of the truth that God does not change and that God interacts with the creature in the most personal of ways? In his Institutes of Elenctic Theology, Francis Turretin sought to answer the many questions that arise when we consider this subject. He wrote,
"(1) Scripture expressly attributes it to him: “I am the Lord, I change not” (Mal. 3:6); “the heavens shall perish, but thou shalt endure” (Ps. 102:26); “with God is no variableness, neither shadow of turning” (Jam. 1:17). In the latter not only change is denied of him, but even the shadow of change, that he may be contrasted with the sun, the fountain of material light, liable to various changes and eclipses by which its light is intercepted. But God, the father of lights, acknowledges no tropics and can be obscured by no clouds since there is nothing to intercept his influence. The immutability of the divine will and counsel in particular is often asserted: “God is not a man, that he should lie; neither the son of man, that he should repent; hath he said, and shall he not do it? Or hath he spoken, and shall he not make it good?” (Num. 23:19). “My counsel shall stand, and I will do all my pleasure” (Is. 46:10; cf. Pss. 33:11; 110:4; 1 S. 15:29; Heb. 6:17).
Reason confirms it for he is Jehovah, and so a necessary and independent being that can be changed by no one. “All created things are mutable” (pan ktiston trepton), says John of Damascus (Dialogus contra Manichaeos 68 [PG 94.1568]) because they take their being from some other than themselves. God is immutable because he is from himself and recognizes no cause above himself. (2) He can neither be changed for the better (because he is the best) nor for the worse (because he would cease to be the most perfect). Augustine says, “Whatsoever is changed from the better for the worse, and from the worse for the better, is not God, because perfect virtue can neither change for the better, nor true eternity for the worse” (Tractate 23*, On the Gospel of John [NPNF1, 7:154; PL 35.1588]). (3) All causes of change are removed from him: dependence a priori; passive power; error of mind; inconstancy of will.
Creation did not produce a change in God, but in creatures; not a physical change and properly so called (which supposes its material), but hyperphysical by which the creature passes from nonexistence to existence. An agent said to be changed (which in itself becomes different from what it was before), but which becomes different (not in itself but only relatively and in order to another thing) cannot be said to be changed. Now when God became the Creator, he was not changed in himself (for nothing new happened to him, for from eternity he had the efficacious will of creating the world in time), but only in order to the creature (because a new relation took place with it). And as to the act of creation being transient not immanent, it is not so much in God as from him.
God was not changed by the incarnation; the Word (logos) was made flesh, not by a conversion of the Word (tou logou) into flesh, but by an assumption of the flesh to the hypostasis of the Word (logou).
It is one thing to change the will; another to will the change of anything. God can will the change of various things (as the institution and abrogation of the Levitical worship) without prejudice to the immutability of his will because even from eternity he had decreed such a change. So from eternity he decreed to create the world and preserve it until a certain time, but afterwards to destroy it with a flood. In the same manner, we must reason concerning his knowledge. The knowledge of God does not change with the thing known because God who knew it not only knew that this change would take place, but even decreed it.
It is one thing to be indifferent to various objects; another to be mutable. The cause of indifference is not mutability, but liberty. The will of God could be indifferent before the decree, but after the decree it cannot be mutable.
The power of varying his own acts is not the principle of mutability in itself, but only in its objects (unless it is understood of the variation of his own acts which a perfect will does not vary, but only an imperfect; for no one can vary his purpose unless some disadvantage is discovered attending it, which cannot be the case in God).
It is one thing to inquire whether God might have determined himself to other objects than those he has decreed before he had resolved anything concerning them; another whether the decree having been formed he could rescind it. The latter we deny, but the former we assert. And yet no mutability is thus charged upon God because he is therefore said to be changed (who begins to will what he nilled or to nill what he willed) which can have no place in God.
Repentance is attributed to God after the manner of men (anthrōpopathōs) but must be understood after the manner of God (theoprepōs): not with respect to his counsel, but to the event; not in reference to his will, but to the thing willed; not to affection and internal grief, but to the effect and external work because he does what a penitent man usually does. If repentance concerning the creation of man (which he could not undo) is ascribed to God (Gen. 6:6, 7*), it must be understood not pathetically (pathētikōs), but energetically (energētikōs). Although he could not by a non-creation undo what he had done, yet by a destruction he could produce change.
Unfulfilled promises and threatenings do not argue a change of will because they were conditional, not absolute. This is evident from Jer. 18:7–8*. Although the condition may not often be expressed, it must be understood as tacit and implied.
When the death of Hezekiah was predicted, there was not a declaration of what would happen according to the will of God, but of what (according to the nature of second causes) would happen unless God interposed.
The necessity of the immutability we ascribe to God does not infer Stoic fate. It is only an extrinsic necessity and from the hypothesis of the divine will, without interference with the liberty and contingency of things, as will be proved hereafter when we come to the decrees."
1. Francis Turretin, Institutes of Elenctic Theology, ed. James T. Dennison Jr., trans. George Musgrave Giger, vol. 1 (Phillipsburg, NJ: P&R Publishing, 1992–1997), 205–206.