What is the mission of the church? That was the sermon topic one Sunday as I visited a friend's church, but I found my mind wandering. I had just signed a contract to write a book on Christian world-view, and I was experiencing writer's remorse. Did this book really need to be written?

Suddenly the pastor's words jarred me back. The mission of the church, he said, is to prepare for Christ's return in five ways: prayer, Bible study, worship, fellowship, and evangelism. In that instant, all lingering doubts about the book were erased. Prayer and worship are central to the church's life, of course; but we can never overlook our responsibility to redeem and restore all of culture. Though well intentioned, the pastor's words were a sure prescription for the continued marginalization of the church.

Yet his message is typical of evangelicalism. Our movement's great strength—yet also its weakness—is defining faith in terms of personal salvation alone. Though this focus on conversion has fueled great evangelical fervor, it has also made soul-winning an end in itself. Yet we are not only saved from sin, we are also saved to something: to the task of developing God's creation.

Genesis teaches that on the first five days, God did the work of creating directly. But on the sixth day, he formed human beings in his image to carry on his creative work, commanding them to fill and subdue the earth (Gen. 1:28). This is the "cultural commission," and it is just as binding as the Great Commission. It means we must go beyond personal conversion and develop a faith that encompasses every part of life—every sphere of work, every aspect of the world.

In short, a world-view.

Developing a world-view is not some ivory-tower exercise; it ...