Michael Horton writes:
“When Jesus Christ arrived, He did not revive the Sinai theocracy as His contemporaries had hoped. Instead of driving out the Romans, He commanded love for our enemies. Gathering the new Israel — Jew and Gentile — around Himself, by His Spirit, through Word and sacrament, Jesus inaugurated the kingdom of grace that will be manifested one day as a kingdom of glory. In this time between His two comings the wheat grows together with the weeds, the sons of thunder are rebuked for calling down judgment here and now on those who reject their message, and the faithful gather regularly for the apostles’ teaching, fellowship, the breaking of the bread, and the prayers (Acts 2:42). Through its administration of Gospel preaching, baptism, the Supper, prayer, and discipline, the church is God’s new society inserted into the heart of the secular city as a witness to Christ and the age to come when He will be all in all.
In our Christian circles in the United States today, we can discern a “Christendom” view, where some imagine America to be a Christian nation invested with a divine commission to bring freedom to the ends of the earth. Of course, Christians have an obligation both to proclaim the heavenly and everlasting freedom of the Gospel and the earthly and temporal freedom from injustice. But they are different. When we confuse them, we take the kingdom into our own hands, transforming it from a kingdom of grace into a kingdom of glory and power.”
For the rest of the essay, go here.
For a fine introduction to the contemporary Reformed recovery of the doctrine of two kingdoms, see David VanDrunen’s Living in God’s Two Kingdoms.