David Gibson has helpfully explained:
“The church is God’s new humanity, an example of the future new creation given in advance to the old creation, a sign of the world to come where everything is brought together under the unending reign of Jesus the King.
“This means that expository preaching, because it is addressed to people whose very existence is defined by the world to come, constantly draws on the reality of the next world to help make sense of the present world. The doctrine of the church ensures that preaching is addressed to “strangers in the world” (1 Pet. 1:1) and provides the challenge to “live self-controlled, upright and godly lives in this present age while we wait for the blessed hope-the glorious appearing of our great God and Saviour, Jesus Christ” (Titus 2:12-13). Preaching for the church roots its ethical imperatives in the eschatological reality of both coming judgment and promised reward (2 Pet. 3:11-14). It interprets suffering as a participation in the frustrated groans of a cosmos waiting for its liberation, and holds out the comfort that “our present sufferings are not worth comparing to the glory that will be revealed in us” (Rom. 8:18-21). It also means that the proclamation of the gospel does not offer a dualistic “saving of the soul” or merely a “ticket to heaven.” Instead, ecclesiology ensures that expository preaching heralds a whole new way of being human in the world-reconciliation to God and to others by participating in the first-fruits of the new creation.