Thy Kingdom Come

Question 102: What do we pray for in the second petition?
Answer: In the second petition, which is, Thy kingdom come, we pray, that Satan's kingdom may be destroyed; and that the kingdom of grace may be advanced, ourselves and others brought into it, and kept in it; and that the kingdom of glory may be hastened. (WSC)

We pray that God’s kingdom would come. This coming is further explained by the phrase that concludes the first three petitions of the Lord's Prayer, "on earth as it is in heaven." God's kingdom comes to earth from heaven. The Gospel of Matthew usually calls it the "kingdom of heaven" even while teaching that it comes to earth. When man sinned, earth revolted from heaven and joined Satan’s kingdom, but now the king has come and God is reasserting his reign on earth. 

When does God’s kingdom come? It came with Jesus’ coming, as he himself proclaimed (Matt. 4:17, Luke 11:20). It comes more and more throughout this age, as a tree grows and as leaven works in bread, not all at once (Matt. 13:31-33). It will come in its consummated state when Jesus returns and judges all men, glorifying his people and purifying and restoring creation (Matt. 13:36-43, 2 Peter 3:4-13).

The kingdom of God is administered by Jesus in his capacity as our mediator. It comes by his gospel and Spirit at work in the salvation of sinners (“the kingdom of grace”) and by his providence and judgment (“the kingdom of his power,” see WLC 191 below). Only by being born again by water and the Spirit can a person enter the kingdom of God (John 3:5). Within this kingdom there is peace and protection through Christ the king. The kingdom comes as the word is preached, as disciples are baptized and trained, as they obey the king willingly in all areas of life, and as Christ guides history for the sake of his church. The world is transformed by this process, as dough is transformed by leaven. As Calvin comments, 

"The substance of this prayer is, that God would enlighten the world by the light of his Word, — would form the hearts of men, by the influences of his Spirit, to obey his justice, and would restore to order, by the gracious exercise of his power, all the disorder that exists in the world." 

The visible church is the institutional expression of this kingdom in history (Matt. 13:47-50) and its officers bear the “keys of the kingdom” (Matt. 16:18-19, 18:17-20). The members of the visible church manifest the reign of Christ as they confess him as Lord and Savior and serve him in every sphere of human endeavor with “righteousness and peace and joy in the Holy Spirit” (Rom. 14:17). When he returns, the kingdom will be brought to perfection and glory (“the kingdom of glory”).

Here is the Westminster Larger Catechism’s version of this answer:

“In the second petition, (which is, Thy kingdom come,) acknowledging ourselves and all mankind to be by nature under the dominion of sin and Satan, we pray, that the kingdom of sin and Satan may be destroyed, the gospel propagated throughout the world, the Jews called, the fullness of the Gentiles brought in; the church furnished with all gospel-officers and ordinances, purged from corruption, countenanced and maintained by the civil magistrate: that the ordinances of Christ may be purely dispensed, and made effectual to the converting of those that are yet in their sins, and the confirming, comforting, and building up of those that are already converted: that Christ would rule in our hearts here, and hasten the time of his second coming, and our reigning with him forever: and that he would be pleased so to exercise the kingdom of his power in all the world, as may best conduce to these ends.” (WLC, Q. 191)