When Karl Barth, retired and in his later years, visited an American theological school, one of the students asked him, "How would you characterize your theology, Dr. Barth?" Barth thought for a moment and said that his answer was a song he learned at his mother's knee: "Jesus loves me, this I know ..." Isn't that great! A renowned theologian, no stranger to using all his mind as he deals with the meaning of the gospel, wrapped it all up in a little Sunday school tune. Alongside his wide-ranging academic theology, he had an everyday theology.
Note: This often cited story appears to be true as an eye witness has corroborated it. See this blog and the authors attempt to verify the information: https://www.patheos.com/blogs/rogereolson/2013/01/did-karl-barth-really-say-jesus-loves-me-this-i-know/