Eugene H. Peterson’s Under the Unpredictable Plant (Grand Rapids: Eerdmans, 1992) is one of those books to which I keep returning to be challenged and yet encouraged. One of my favorite sections of the book is where he describes the novelist Chaim Potok’s (1929–2002) lecture at Johns Hopkins in the 1980s. Potok’s Jewish mother tried to make him a brain surgeon while he wanted to be a writer. Her logic was simple and clear: he could keep many from dying; he could make a lot of money, to which, however, Potok always answered, “No, mama. I want to be a writer.” Peterson writes that, according to Potok, the same conversation was repeated every time Potok came home for break from college. The climax of the story is worth quoting in full:
“The exchanges accumulated. The pressure intensified. Finally there was an explosion. ‘Chaim, you’re wasting your time. Be a brain surgeon. You’ll keep a lot of people from dying; you’ll make a lot of money.’ The explosion detonated a counter-explosion: ‘Mama, I don’t want to keep people from dying; I want to show them how to live!'” (47).
I appreciate that Potok was able to see that there’s something deeper, more profound, and even more urgent than keeping people from dying a physical death.
Heart surgeons–cardiologists; this word comes from the Greek καρδία [kardia] “the heart”–can save people’s lives (and, of course, make a lot of money), too. When I tried to see if there were useful and informative talks or lectures on regeneration or the regenerated hearts, YouTube gave me an interesting list of search results. See some of them below:



As you see, most of the clips concerned the physical heart, the fist-sized blood-pumping organ in your body. The first three videos captured above seem to argue that there is a way to regenerate the heart, which is fascinating.
But my concern was not about the physical heart (心臓) but about the different kind of heart (心[こころ]). The kind of heart that is not only foolish (Romans 1:21) but also unrepentant (Romans 2:5) unless the Spirit of God regenerates it. Acts 2 shows how regeneration can transform us. When the crowd heard Peter’s speech at Pentecost, they were pierced to the heart and cried “What shall we do?” (v. 37). The unrepentant (hence unregenerate) heart will never recognize its sinfulness and need for a Savior. But the heart that has been regenerated by the work of the Holy Spirit will accept the gospel, repent, and believe in the name of Jesus Christ for the forgiveness of their sins (v. 38).
Although some cardiologists seem to be confident that they can “regenerate” the heart, the true regeneration of the “true heart” is solely the work of the Holy Spirit, without which no one comes to Christ.