Tim Keller said he would never forget the story about one of his mentors, a college professor named Dr. Addison Leach.

Two young women at the college were both bright and their respective parents wanted them to get Master’s Degrees and go on to careers. But, instead, they both became Christians. Both decided that they were going to become missionaries. Their parents had a fit. One of the mothers called Dr. Leach, thinking that Dr. Leach was one of the reasons that the girls had become (in the mother’s words) “religious fanatics, rather than pursuing the course they had hoped, getting a career and having security. Instead, they were going to go wildly off into the blue.”

This mother said, “We wanted our daughter to get a master’s degree, start a career, and get something in the bank, so she could have some security. Dr. Leach responded:

Please just let me remind you of something. We’re all on a little ball of rock called earth, and we’re spinning along through space at zillions of miles per hour. Even if we don’t run in to anything, eventually we’re all going to die. Which means that under every single one of us there’s a trap door that’s going to open one day and we’re all going to fall off this ball of rock. And underneath will either be the everlasting arms of God or absolutely nothing. So maybe we can get a master’s degree to get some security.

But the biggest savings account in the world cannot stop cancer. It can’t stop traffic accidents. It cannot stop broken hearts. It can’t give you anything … any of the things that only God can give you. He’s the only significance you can have. He’s the only love that you can get and can’t lose.