My wife and I have been blessed with four wonderful children, each delightfully unique. Let me focus on my sons, for a moment. Robert, is the first-born, and Stephen, the second, is two years younger.

Today is a day of expected departure. Stephen is already off to a nearby college (George Fox University), studying on nearly full-ride scholarships. This evening we take Robert to an airport hotel and tomorrow go back to watch him be inducted into the U.S. Army. Early the following morning he flies off to basic training at Fort Benning, Georgia.

My sons love to hear me tell the story of one of their teachers several years ago. The teacher came to me and said that he understood my thinking on a subject because he, who had been talking with one of my sons, assumed I thought like my son. To which my cryptic reply was, "Which son?"

When they were younger, I loved to throw out a topic, any topic, and watch them tear into it with much gusto like two puppies on an old slipper, each picking sides as long as it was opposite the other. As they grew older, I no longer needed to suggest a topic - they were well over my head by then, whether the issue be science, math, history, literature, media and the arts, politics, theology, ethics or whatever. OK, I still surpass them in theology and ethics (I have a Ph.D. to defend after all). But I can in most fields raise a third angle, because on nearly every issue in life there is always one more option to consider. They were home together one last time about a week ago. As Kim and I went to bed, I fell happily asleep listening to them discussing some random topic with great intensity.

The pursuit of life for each of my kids, including these boys, is not just an intellectual exercise. Life is about fervent activism. Stephen, a declared pacifist, wants to pursue his field (math) for the sake of helping kids. Robert is joining the army and wants to go into the infantry - so he can be, literally, on the ground with the people he has come to help. They are both passionate about injustice in our world and are finding their own unique ways of making a difference.

I will miss their intellectual wranglings. Who can guess how many more of those cerebral wrestling matches I will enjoy hearing? As I see Robert leave, I have feelings of pride and of loss: pride that he is making his own way in this world, loss that I must now let him go.

My mother once told me I could do whatever I felt I should do in life as long as I kept my center in Jesus. And that is the same admonition I leave with my boys. There are very few absolutes in life and sometimes it is hard to know what is and is not essential. But this much I know, and I know they know, that whatever else may or may not be true, our center is in Jesus Christ. I wish Robert well and will always, no matter what, leave the light on for him.