Here is one striking parable he uses, based on Jonah’s extraordinary comment on hearing that the Ninevites had repented: “death is better for me than life.” Keller explains:

During the building of Interstate 79 from Pittsburgh to Lake Erie, one stretch remained unfinished for years because of a swamp that had to be crossed. They kept putting down pilings, trying to finally get to the bottom so the bridge would not sink. But whenever they thought they had gotten to bedrock, the piling would give way and they would have to drill deeper.

Jonah’s heart was like that. Every time it seemed he had taken God and his grace to the very bottom, it turned out that he needed to go deeper. What does it mean to get to “bedrock” in one’s heart? If you say, “I’ll obey you, Lord, if you give me that,” then “that” is the nonnegotiable and God is just a means to an end. “That” - whatever it is - is the real bedrock. It is more foundational to your happiness than God is.

As long as there is something more important than God to your heart, you will be, like Jonah, both fragile and self-righteous. Whatever it is, it will create pride and an inclination to look down upon those who do not have it. It will also create fear and insecurity. It is the basis for your happiness, and if anything threatens it, you will be overwhelmed with anger, anxiety and despair.

To reach heart bedrock with God’s grace is to recognise all the ways that we make good things into idols and ways of saving ourselves. It is to instead finally recognise that we live wholly by God’s grace. Then we begin serving the Lord not in order to get things from him but just for him, for his own sake, just for who he is, for the joy of knowing him, delighting him, and becoming like him. When we’ve reached bedrock with God’s grace, it begins to drain us, slowly but surely, of both self-righteousness and fear.