Why do I serve where I serve, and why do I do the things that I do?

As someone who has taught seminary students for more than fifteen years, I worry about the rising number of seminarians who, when asked where and how they think they might best serve, respond with something like this: "Well, I think I would like to teach somewhere. Every time I have taught, people have told me I have done a pretty good job. I get a tremendous sense of fulfillment out of teaching the Bible. I think I could be satisfied teaching Scripture."
How pathetic. I know pagans who find satisfaction and fulfillment by teaching nuclear physics. In any Christian view of life, self-fulfillment must never be permitted to become the controlling issue. The issue is service, the service of real people. The question is, How can I be most useful?, not, How can I feel most useful? The goal is, How can I best glorify God by serving his people?, not, How can I feel most comfortable and appreciated while engaging in some acceptable form of Christian ministry? The assumption is, How shall the Christian service to which God calls me be enhanced by my daily death, by my principled commitment to take up my cross daily and die?, not, How shall the form of service I am considering enhance my career? This is not to deny that Christians may derive joy from work honestly offered to God, whether that work is vocational ministry or research into the properties of quarks. But it is one thing to find joy in the work to which we have been called, and another to make joy the goal of life, the fundamental criterion that controles our choices. It is one thing to weigh a Christian leader's evaluation of our gifts, and another so to focus on our perception of our gifts that self-worship has crept in through the back door. It is one thing to think of people as a live audience that will appreciate our displays of homiletical prowess, and another that passionately shapes each sermon to convey the truth to God's people for their good.

- p. 82-83, A Call to Spiritual Reformation by D. A. Carson

What challenging words. What truth! How often I take good works that God has called me to do into a kind of performance before them for my praise and sense of fulfilment! O, that God would bring a reformation in my heart!