For many of us, "eschatology" is one of those fancy words that theologians toss around to intimidate the uninitiated. A plain English definition of eschatology is intimidating enough. It means the study of the "last things."
Eschatology is usually concerned with the biblical themes of the end of history, the return of Christ, the final judgment, and the establishment of God's reign. Activist Christians tend to concentrate on the important task of shaping a faithful discipleship around more immediate issues and concerns. As a result, any talk of the last things is often labeled the kind of abstract theological exotica that only serves as a way to avoid more concrete questions of commitment.
But eschatology is not just an obscure subdivision of Christian theology. From the time of the earliest prophets' vision of the messianic age of righteousness and peace, eschatology has been at the very center of biblical faith. Jesus' first message, "Repent, for the kingdom of God is at hand," and his many parables about the coming of the kingdom, were deeply concerned with eschatology.
Confidence in Christ's ultimate victory animated the witness of the early Christians as they sought to live as the first fruits of what the apostle Paul called the "new creation." The allegory of Christ's ultimate triumph over the powers of sin and death contained in the Revelation of John recalled and rekindled that confidence when it began to flag in a later era of severe persecution.
The whole of the biblical witness tells the story of God's efforts to redeem human history and bring it to fulfillment. The role of the people of God in this story is to be both the agent of God's redemptive activity and a living model of the new creation. We are called to live in the kingdom here and now even as we await its fulfillment and spread its good news.