A seminary student and I were walking around the lake on a beautiful evening. We had begun the walk in part for exercise, and in part because he wanted to talk about his vocation. He had begun to think seriously about his ministerial identity, his spiritual formation, and the oscillating sense of excitement and apprehension he felt about how others would perceive him as "the minister."

We had a stimulating and wide-ranging conversation about the church, seminary life and the challenges seminaries face with issues of formation, education and malformation. We discussed the importance of spiritual discipline and the ways in which the student would need to develop practices and habits of prayer in order to sustain his strong commitment to a ministry of social justice.

Toward the end of the conversation, he shifted the topic to an issue specific to his formation: marriage. How do you know, he wondered aloud, when you have discovered the best person to marry? I quickly responded that you never really know for sure--marriage is a commitment you make in faith and hope and love. He said he understood all that; he didn't mean "know" in the sense of certainty. I realized that he was asking how, amid the many uncertainties of life, you discover that a particular person is the one with whom you will make a lifelong commitment.

The student followed his initial question with one that got specific and personal: how had I concluded that my wife was the person I wanted to marry? I somewhat nervously offered a series of quips designed to deflect the question. But I also realized that I owed him a response equal to the thoughtfulness and seriousness of his concern.

I began with the obvious. You need to be sure that you are attracted to the person and that you enjoy spending time with that person. There should be a basic compatibility. However, a good marriage needs to go much deeper than that.

I paused. How does one describe depth? I recalled the dynamics of my own marriage, and the ways in which that commitment had enabled me to change and grow over the 16 years since I was in the student's situation. In that light, I suggested that in marriage, you are making a determination about the kind of person who will significantly shape your character amid the vicissitudes of life.

Alas, the student wanted me to say more. And I felt the burden of saying something thoughtful, something more than a banal truism about the risks of making any commitment. I thought about character, and about why I am so sure now that marrying my wife was critical to my own Christian formation.

Finally, I said: You should want to marry someone who will challenge the vices you have come to love, and affirm the gifts you are afraid to claim. We both sensed that I had stumbled onto a formulation that was worth further reflection, but we decided to pursue it on another occasion.

What was I trying to say in that formulation? Perhaps that it seems obvious that we would be drawn to people who reflect and reinforce our vices as well as our virtues. They provide us with a strong comfort zone. Further, it seems clear that insofar as we want to be challenged and encouraged, we typically want to be challenged to give up those vices we already hate and be encouraged to enhance those gifts we already exemplify.

It seems less obvious that we would want to live with someone who would challenge us to give up the vices we love and to affirm the gifts we are afraid to claim. But this is where our real growth in character will occur. This kind of challenge is also crucial to nourishing a healthy marriage.

To be sure, such growth involves commitment, takes time and requires trust. It involves a commitment that we will give of our own lives sufficiently to allow that relationship to shape our character. It takes time for us to believe that another person understands us well enough to know where our real vices and gifts are to be found. It also requires trust that the other person genuinely wants us to grow, that the challenge and affirmation the other offers are not primarily self-interested or a reflection of competitive power dynamics.

This trust can be cultivated only if the challenge is also balanced by the affirmation. We know of relationships where people consistently challenge only our vices (both those we hate and those we love), and we avoid them because they are excessively critical. We also need affirmation of who we are and who we might become if we claimed the gifts that others discern in us.

No one can predict the joys and griefs, the hopes and fears, the expected and unexpected circumstances that undoubtedly affect the dynamics of a particular marriage. Amid those uncertainties, however, we can seek to discern those qualities in another person that will help guide us through life. Of course, this is not unique to marriage. We hope that close friends will also challenge our vices and affirm our gifts. Even more, we long to discover committed Christian communities that offer such support and challenge.

I realized that the two primary analogies I was thinking about were my own marriage and the patterns of Wesleyan class meetings. In both settings, challenge and support offer a paradigm for growth in Christian life.

It is never easy to expose ourselves to being challenged to give up our vices and to claim our gifts. Yet we are invited to do so in and through commitment to such relationships as marriage, friendship and Christian community. Such relationships are a school where we learn what it means to love God as God has first loved us. Our commitment shapes our character, even as our character shapes our commitment. That may not make the risk of commitment easier, but it provides a context for helping us discover its life-giving potential.