Systematic Theology – Paterology (10) – Immutability

Systematic Today marks the first doctrine which is truly interwoven with preceding doctrines. Today we will be discussing the doctrine of God’s unchangeable nature, Drawing from the Latin word for “changing” (mutabillis) combined with the Latin negative pefix (in-) this doctrine is formally called Immutability. Although this doctrine is sometimes seen as a way to make God cold and distant, and thus is seen as something unfriendly to the Gospel… we shall see below that it is actually the foundation of the hope we have in Christ.

Exegetical Considerations

Although I will not always be mounting an exegetical defense of the doctrine in question, two doctrines in particular (Immutability and Impassibility) are often critiqued for being philosophical accretions with little biblical support. While it is true that Greek philosophical categories have shaped and influenced the way we understand the primarily Hebraic way of talking about God, the application of these Greek categories has a solid biblical grounding.

The first of the primary proof texts for this doctrine is found in Malachi 3:6:

For I the Lord do not change; therefore you, O children of Jacob, are not consumed.

This passage explicitly says that the Lord is not subject to change, and because of this immutability his covenant promises are secure (a theme that will be picked up in a later proof text).

This idea is picked up in the New Testament by James (1:17) when he writes:

Every good gift and every perfect gift is from above, coming down from the Father of lights with whom there is no variation or shadow due to change.

James here, again roots the blessings that are ours in Christ in the fact that God does not change. Possibly referring to, and rejecting, the works of the pre-Socratic philosopher Heraclitus, he argues that God has no variation or shadow due to change. Heraclitus argued that the only thing that truly exists is change, and one of his favored metaphors was the turning of a tuning key on an instrument. Specifically identifying that God’s goodness is unchanging due to a lack of variation or shadow of turning, James clearly argues that the truly existing one is the unchanging, yet ever active, God. As a side note, if it is true that James is referencing the works of Heraclitus… it sets a pretty clear precedent for the use and appropriation of philosophical categories by the people of God.

Finally, we see the author of Hebrews (6:17-18) also appeals to God’s unchanging nature to establish the certainty and permanence of his promise:

So when God desired to show more convincingly to the heirs of the promise the unchangeable character of his purpose, he guaranteed it with an oath, so that by two unchangeable things, in which it is impossible for God to lie, we who have fled for refuge might have strong encouragement to hold fast to the hope set before us.

Doctrinal Interdependence

As I mentioned above, this doctrine is the first truly interdependent doctrine we will examine. It is rooted primarily in two paterological doctrines we have already discussed.

Simplicity – While it is a difficult concept to grasp, the doctrine of simplicity not only provides support for immutability… but actually demands that we hold it. All creatures are made up of components. Some are physical components (body parts), some are metaphysical components (spirit and body), yet others do not necessarily fit either of these categories. An example of the last is the idea of Potential and Actuality. As we grow and develop, we both exist in a given state (actual) and we have a future state (potential). This composition explains why we change over time. We cease to be what we were, and we become what we are not (this will become an important phrase when we get to Christology… so tuck it away in the back of your mind). However, God is not like that. What he is, he has always been. What he has always been, he always will be. Another way to say it, although laden with Barthian and Thomistic implications that we may not always agree with, is that God is pure actuality or pure being. That is to say that because of God’s simplicity, his state of not being composed of parts, God can either be pure potential (meaning he does not in any way exist) or pure actuality (meaning he has no potential to be something other than what he is).

Aseity – Beyond the implications of the above doctrine, God also cannot be changed by anything external to himself. This excludes all forms of Process Theology or Open Theism, which explicitly argue that God develops over time (Ontologically in the former, and in terms of awareness and knowledge in the latter). Because God is not dependent on anyone outside of himself for his existence or identity, he could not be changed.


As I mentioned above, this doctrine is absolutely vital to the Gospel. In all three of the proof texts given above, God’s blessing toward us is rooted in his unchanging nature. We can be sure that God is not fickle, and that his promise is sure. If God were mutable, then we could not be sure that his promise would not be made void by some later development. Rather than have a sure hope in the certainty of his promise, we would always have to wonder if his covenant would last or be replaced. Instead, as the author of Hebrews argues, we can know that his promise is unchangeable for two reasons. First, God is immutable. Second, that which God swore upon (himself) is immutable. Thus we can be doubly sure that the promise itself is secure and immutable.