God’s “Constancy,” as Barth refers to his preferred term for Immutability, is a key doctrine in regard to God’s constant steadiness of ousia (being), as Father, Son, and Holy Spirit (hypostases). But when a notion of immutability is derived from the classical Greek philosophers rather than what is Self-revealed in God in Christ, we end up with a notion of godness that ends up having no correlation between the living God and a god of phantasm. Below, Barth is driving this point home as he relates it to a theology of prayer.
The objection that God cannot hear man’s prayer without as it were “losing face,” without abandoning Himself in some sense to the creature, fades into nothingness when seen in this light. If ever there was a miserable anthropomorphism, it is the hallucination of divine immutability which rules out the possibility that God can let Himself be conditioned in this or that way by His creature. God is certainly immutable. But He is immutable as the living God and in the mercy in which he espouses the cause of the creature. In distinction from the immovability of a supreme idol, His majesty, the glory of His omnipotence and sovereignty, consists in the fact that He can give to the requests of this creature a place in His will. And does He not do this in profoundest accord with Himself by doing it precisely where in the creation He is concerned with Himself, His beloved Son and those who are His? It obviously takes place in complete faithfulness too Himself when He lets the creature, in its unity with Himself, participate in His omnipotence and work, in the magnifying of His glory and its own salvation, by commanding it to ask and hearing its requests, and when He truly gives it a place at His side in the kingdom of grace and the kingdom of the world. God cannot be greater than He is in Jesus Christ, the Mediator between Him and man. And in Jesus Christ He cannot be greater than He is when He lets those who are Christ’s participate in His kingly office, and therefore when He not only hears but answers their requests. And therefore it is not an insolent but a genuinely humble faith, not a particularly bold but simply and ordinary Christian faith, which is confident and assumes that God will grant what it asks, indeed that He has already done so even as it asks. This faith is not, then, an additional and optional achievement for religious virtuosos. It is absolutely obligatory for all those who want to pray aright. Any doubt at this point is doubt of God Himself, the living God who in Jesus Christ has entered into this fellowship and intercourse with His creature. Any vacillation or questioning is the horrible confusion of God with that immovable idol. The worshipper of the idol must not be surprised if he calls upon it in vain. But true reverence and humility before God, and real submission to His will, are to be found when man adopts his allotted place in that fellowship with God, when he enters into that intercourse with Him, when he takes quite seriously acceptance of His command and promise, and therefore when he is no less certain of the hearing of his request than of the God to whom he turns. For this God is not only occasionally but essentially, not only possibly and in extraordinary cases but always, the God who hears the prayers of His own.[1]
The so-called ‘classical theist’ (a very modern term, by the way) would kick hard against these goads. Even so, the case remains that the living God will not be circumscribed by the profane categories of human machination. If the Christian is genuinely committed to the ‘Scripture Principle,’ and its attested reality in Jesus Christ, then what Barth is saying should resonate deeply with the Christian heart of hearts. We worship the God who is Father of the Son by the Holy Spirit’s bonding fellowship of eternal koinonia and Self-giving, one for and in the Other, love. Not only has God spoken, and doth speak, but He also listens to and hears our prayers, as if ascending incense wafting over His triune nostrils. If He won’t listen to us as our Father, who really will? What a hope the Christian has. We are never alone. Our God, as Father of the Son by the Holy Spirit who He is, will never leave or forsake us! amen
[1] Karl Barth, Church Dogmatics III/4 §53 [109] The Doctrine of Creation: Study Edition (London: T&T Clark, 2010), 102–03.