In The Enduring Authority of the Christian Scriptures, Graham Cole quotes A.J. Heschel on the God of Israel as a name, not a notion:
There is a difference between a ‘name’ and a ‘notion.’… A notion applies to all objects of similar properties. A name applies to an individual. The name ‘God of Israel’ applies to the one and only God of all men. A notion describes, defines, a name evokes. A notion you can conceive; a name you call.
God is not a concept. He is not a variable we plug into our theological formulae, nor a placeholder, nor some sort of ambiguous cipher. He isn’t a set of abstract attributes, a cosmic vending machine, a tool to be manipulated– he is the Lord of Hosts, the Holy One of Israel, who has given us his name.
We may think that there are a good number of unbelievers, very selfish Christians or weird cultists out there who need to hear and understand this about God, and no doubt they do. But if judgment is to begin, let it begin with the household of God. Do evangelicals treat God as though he is less than a person, a name? I think sometimes we do. When we read the Scripture flatly, by taking a theme and using Scripture verses to fill it out irrespective of their aims and contexts, we treat the Word of God and God himself in this way. When we take an attribute or quality of God and surmise endlessly on it, we treat God as something less than who he has revealed himself to be. When we gravitate again and again to the Jeremiah 29:11s of the Bible– irrespective of context– and ignore the Deuteronomy 28:29s, for example (“You will be unsuccessful in everything you do; day after day you will be oppressed and robbed, with no one to rescue you.”)– then we demean God as the sovereign Lord and seek to use his Word to take his place.
We must recognize and submit to this, that it is the God of the Scriptures with whom we have to do, not some notional figment cast and recast again in our own image as cultural winds demand. The God and Father of our Lord Jesus Christ has revealed himself to us, and he has done so as the named God, not the notional god.