We buried a fine teacher the other day. He was not a scintillating lecturer, nor was he a particularly exciting person. But he was an excellent scholar, and his passion for his subject matter, for the life of the mind and for his students all shone forth brilliantly. As I looked out over the congregation gathered for his memorial service, I saw students who had traveled long distances to remember him, and recalled the difference he had made in many people's lives.

Henry Adams said, "A teacher affects eternity; he can never tell where his influence stops." I read those words in Tuesdays with Morrie, Mitch Albom's beautiful tribute to one of his teachers. Twenty years after he had graduated from college, long after he had stopped having any regular contact with Morrie Schwartz, Albom began to visit his beloved old sociology professor. Why? In part because Morrie was dying, but even more because Albom wanted to reconnect with a person who had played a key role in his life.

Morrie was lucky to have one of his students return to reestablish old ties, and to learn about the difference his teaching had made in Albom's life. Too many teachers live only with the unconfirmed hope that their teaching has made a difference. I never took the time to write and thank one of my best and most beloved teachers, a woman who during my high school years sustained hope in my ability and demanded excellence in me. She rekindled my love for learning at a time when it was close to being extinguished. She helped to change my life.

Over a century and a half ago, Ralph Waldo Emerson wrote in his journal: "The whole secret of the teacher's force lies in the conviction that [people] are convertible. And they are. They want awakening." When we encounter teachers who enable that awakening, who challenge our complacency or our smug self-confidence, we may struggle with the changes that occur—but we also are grateful for the growth. In many cases, teachers shape their students' lives with their passion, dedication and excellence.

Over the past few weeks, I have encountered several short essays bearing witness to the importance of teachers. In Newsweek, Robert Samuelson pays tribute to a teacher who not only gave good lectures, but also transmitted "life-changing les­sons." In the New York Times Review of Books, Andrew Delbanco draws on Emerson's thought to insist that English teachers reclaim the vocation of being professors "in the religious sense of that word—ardent, exemplary, even fanatic."

Both essays inspired me to rededicate myself to the holy significance of teaching, and to give thanks for the wonderful teachers whose commitment, witness and teaching had made such a pivotal difference in my life. I also was inspired to get in touch with some of them to express my appreciation.

Yet even as I have been moved by these positive examples, I am also moved by chemist Robert L. Wolke's testimony to the power of bad teaching. In The Chronicle of Higher Education, Wolke argues that too often we assume that "bad teaching can have, at worst, a net educational consequence of zero, inasmuch as it fails to produce any positive effects." He contends that there is such a thing as "negative" teaching—that has a lasting adverse impact on students. He draws on his own experience to make his point, recalling a professor who managed to extinguish, at least for a time, Wolke's interest in a subject.

How many times have we not only missed an opportunity to teach others, but actually extinguished the curiosity, the searching spirit, the openness to intellectual conversion in those entrusted to our care? Teachers occupy a special place of privilege and responsibility, whether they are lecturing at a  college, leading an honors seminar at a high school, beginning to acquaint children with the joy of learning at an elementary school, or instructing people in faith at a church.

We have paid insufficient attention to the roles that teachers play within the church, for good and for ill. Pastors are called to teach the faith to their congregations, just as laity teach in a variety of settings. I recall particular people in my own journey who have been extremely important in shaping my understanding of Christian faith and life—a Sunday school youth teacher who made us think and challenged us to grow, a pastor whose immersion in scripture made its pages come alive for me, a layperson whose passion for serving the poor awakened a deeper understanding of the scope of our faith and commitment, a faithful Bible study leader who has been teaching every week for over four decades.

Unfortunately, I also have been all too aware of poor teachers of Christian faith who have not only missed an opportunity to make the faith come alive for students, but have actually extinguished a love for God and the church that may have already been kindled. There may be no more important position in the church than to be a Sunday school teacher—and yet we often offer only the most minimal training, typically because we are so desperate to have the classroom staffed that we are afraid to ask our teachers to do more than be there on Sunday morning.

What if we really believed that teaching makes a difference? What if we really believed not that teaching is at worst an activity with a net educational equivalence of zero, but that it's an activity with the potential to feed the spirit? What if we became convinced that one of the reasons we have such difficulty in maintaining a love for the gospel among our young people is that we have invested so little in teaching them, in cultivating that passion and interest in the first place?