Immutability & Impassability: Understanding God's Unchanging Nature
An exploration of God's immutability and impassability, examining how these doctrines provide assurance to believers.
(This post was originally written for my coursework at Midwestern Baptist Theological Seminary)
Immutability is the doctrine of God's unchanging, infinite, perfection. "Jesus Christ is the same yesterday today and forever." (Hebrews 13:8 ESV). Immutability is a consequence of God's perfection, and a protection of it. There is no potential in God that needs realizing. There is no progress or growth required of God. There is nothing to be added and nothing can be subtracted. A "natural, logical, and necessary corollary to immutability" is impassibility. (Barrett, None Greater, p.115) Impassibility is the doctrine that God is not susceptible to suffering or emotional fluctuation, but is eternally and infinitely alive and perfectly expressive of unchanging, perfect, and full emotion.
Immutability and impassability are good news to the believer. They guarantee God's capacity for mercy and forgiveness and love. They are the assurance of his promises. They are the solid ground upon which we may approach his throne of grace with confidence because "…with [God] there is no variation or shadow due to change." (James 1:17) This is the truth that James uses to secure our hope in the promise of good and perfect gifts coming from the Father, and to dispel our rebellious suspicions that perhaps God is tempting us in our trials. Fainthearted believers can be assuaged of their fear that perhaps God like their human father, arbitrarily angry and displeased with them for unknown reasons. God reveals himself to Moses in Exodus 34:6-7 as immutably "merciful and gracious, slow to anger, and abounding in steadfast love and faithfulness, keeping steadfast love for thousands, forgiving iniquity and transgression and sin, but who will by no means clear the guilty…" And therefore the proud, boasting, sinner can be disabused of their false idea that they can fool God, mocking him with their disobedience, thinking they will be able to sneak past God's notice, or otherwise appease him with outward showing of piety.
What of the myriad references to God's emotional responses, in the scriptures? There are two important points that I can think of.
First, God is an altogether different kind of being than we are. He is not a super-awesome kind of human, he is that he is (Exodus 3:14). Even the use of the pronoun "he" can be misleading if we don't understand the second point below. Every description of God in the Old Testament that describes him in human terms is therefore anthropomorphic, and not to be taken as precise and literal. (Example, God is a spirit, spirits do not have limbs, but the bible speaks of God's arms.)
Second, how are we to understand what anthropomorphic language is intended to communicate? By way of analogy. Since God is infinite in his perfections, and wholly other than we are, language about God is always analogical, not univocal (precise, literal, and always the same in every context) or equivocal (open to multiple possible meanings or interpretations). Analogical language is the best way we are capable of speaking about God, as the images are clear and meaningful, even when they cannot be fully precise.
Therefore, language about God's emotional response to humanity, even if analogical, communicates true things regarding his character, nature, and deeds, in even more helpful ways than precise literalism. God is infinite and perfect, and therefore incomprehensible and ineffable. But he is not unknowable. He has revealed himself to us, using human language in analogical ways, that we might know him truly, though not fully. We have natural limitations (Romans 6:19) that prevent full knowing, until the day we too are glorified, through Christ, at which point we will be able to know fully, and be fully known (1 Corinthians 13:12).