The freedom of God's grace
I thought this was an interesting section of Future Grace by John Piper. I've never thought about Exodus 33:19 quite like this before:
First, when God reveals himself to Moses he virtually defines himself as an absolutely free giver of grace. In Exodus 33:18 Moses says to God, “I pray Thee, show me Thy glory!” God’s first response to this prayer is to give Moses a verbal revelation instead of a visual one. He says in effect, Here is my glory: “I will be gracious to whom I will be gracious, and I will show compassion on whom I will show compassion” (Exodus 33:19).
When God says, “I will be gracious to whom I will be gracious,” he means: I am free in showing grace. If you ask, “Who are those to whom you show grace?” the answer is: “Those on whom I show grace.” In other words, God does not look outside his own will for an impulse to move his grace. Ultimately grace is not constrained by anything outside God himself.
Soon after I finished graduate school in 1974 I devoted about seven years to studying the freedom of God’s grace, preparting to write a book on Romans 9, where this Old Testament text is quoted in verse 15: “For [God] says to Moses, ‘I will have mercy on whom I have mercy, and I will have compassion on whom I have compassion.’” I tried to be fair to all the differing views and to give all the necessary evidence for my conclusions. One of the most important conclusions goes like this: “[Exodus 33:19] is a solemn declaration of the nature of God, or (which is the same thing) a proclamation of his name and glory … It is the glory of God and his essential nature to dispense mercy on whomever he pleases apart from any constraint originating outside his own will. This is the essence of what it means to be God. This is his name.”
So right at the centre of God’s self-revelation is the declaration that he is free in the way he dispenses his grace. And this freedom belongs to the very essence of what it means to be God. God is gracious to whom he will be gracious. He is not limited by anyone’s wickedness. He is never trapped by his own wrath. His grace may break out anywhere he pleases. Which is a great encouragement to the worst of sinners to turn from futile hopes and put their trust in future grace.
Future Grace, Chapter 5
John Piper