In Undaunted Courage, Stephen Ambrose describes the pivotal day when Meriwether Lewis, William Clark and their tiny band of explorers sent their large keel boat back down the river to St. Louis. The boat had carried all of their supplies, weapons and ammunition. It had served as a secure refuge from attack. Now it was gone and they were headed west, toward the Pacific Ocean, alone. Lewis sat in his buffalo-skin tepee and wrote in his journal:

Our vessels consisted of six small canoes and two [larger row boats]. This little fleet, altho’ not quite as rispectable [sic] as those of Columbus . . . were still viewed by us with as much pleasure as those diservedly [sic] famed adventurers ever suffered theirs; and I dare say with as much anxiety for their safety and preservation. We were now about to penetrate a country at least 2,000 miles in width, on which the foot of civilized men had never trodden.

Lewis was reflective that night: “The picture which now presented itself to me was a most pleasing one, entertaining as I do, the most confident hope of succeading [sic] in a voyage which had formed a darling project of mine for the past ten years, I could but esteem this moment of my departure as among the most happy of my life.” It seems to me that Lewis should have been scared to death. He had just watched all visible means of support and sustenance, all security, all contact with the world, sail down the river. And yet he called it the happiest day of his life. It’s almost as if he knew it was his defining moment—the convergence of his particular gifts with a challenge that required those gifts. It’s almost as if Lewis knew, in that moment of radical abandonment and radical trust, the purpose of his life.

I thought about that incident recently as I handed out diplomas to the graduating class of McCormick Theological Seminary. I shook the hands and looked into the faces of the graduates. Some of the graduates know exactly what is going to happen next in their lives. Most, I think, do not.

The journey ahead may be smooth and comfortable, or it may be rocky and even dangerous. But one thing was clear, namely that this was a happy moment, maybe even their happiest moment—to perch there on the edge of the unknown, leaning into the future, uncertain about the journey’s destination. It reminded me of Meriwether Lewis but also, more modestly, of those moments in the lives of each of us when we push out into the unknown with not much more than our trust that God will be with us as we travel. These are joyous and holy occasions.