Jesus teaches us to pray: “Our Father in heaven…Thy kingdom come.”
What does it mean for the kingdom of God to come? To understand this we need to think of the kingdom, not in terms of boundaries or geography, but in terms of a person.
To the Jews Jesus says, “The kingdom of God is at hand…the kingdom is in your midst.” How can that be? When we think of a kingdom we think of geographical boundaries where a certain king has authority to rule. That is sort of the right idea, you just have to cut out the part about geography.
God’s kingdom is wherever Jesus is, wherever His Word is taught, wherever the Holy Spirit is present through the work of the Gospel. So it isn’t about boarders and boundaries. It is about Jesus and the hearts wherein He creates faith.
The kingdom of God is present when one lone Christian sits in the midst of his Muslim neighbors because that one Christian clings to the death and resurrection of Jesus for his salvation. Where the Word is proclaimed and believed, the Holy Spirit is there. And where there is the Spirit, there God is reigning.
And our prayer is that this kingdom of God would grow, that it would advance, that it would finally conquer the earth at the return of our Lord Christ.
The kingdom of God grows within us as Christians, both individually and corporately, when we are led to stronger faith and fiercer love. Christians grow in faith as the Word of God works on their hearts, moving them to repent and believe. Christian love grows as the Spirit uses the Word to inform our newborn souls of how to live God-pleasing lives.
Although we are Christians, baptized into the name of the Triune God, we still possess an imperfect knowledge of God’s Word, both Law and Gospel. We begin as infants in faith and love. We have life to be sure, but that life, just like a baby, needs to grow.
A good illustration of this is Jesus Christ Himself. Although He was born perfect in every way, although He had not an ounce of sin within Him, yet He grew in stature and favor with God and man. He was no more the Son of God at the age of 30 than He was at the age of 3, yet He did grow, and that growth is good.
Christians too grow in Christ. Our sinful nature still holds fast to idolatry and sin. We should not fool ourselves into thinking that we have no idols because we are Christians. Our idols are simply covered in more pious language. Tradition, relevance, family; we place these on pedestals and set them up as rivals to God.
And God, in His mercy, calls us out. His Word points out our worship of these false gods, these pious images and ideas, and He moves our hearts to repent. Then, more gracious still, God forgives us for the sake of the death and resurrection of Jesus. The shed blood of Christ is applied to us so that our idols are torn to pieces and our sins are covered.
That is how a Christian grows in faith. That is how God’s kingdom comes among us. The Spirit of God calls us to repentance and faith through Law and Gospel. The Spirit brings Christ into our midst in Word and Sacrament to forgive, renew, and lead us.
And where the Spirit leads us is out into the world, spreading God’s kingdom to other people and in other places. The kingdom of heaven spreads out, not by conquering territory, but by conquering hearts. That happens through what we usually call “missions and evangelism”.
Of course missions can happen in faraway lands, amongst strange customs and languages. The Lutheran Church has missionaries deployed across the globe. Our congregation specifically has partnered with Rev Joel Fritsche as he goes to the Dominican Republic spreading the Gospel and planting churches.
This can happen, however, closer to home, in your own back yard. Just as the Spirit has had His way with you, convicting you of false worship and leading you to repentance, so the Spirit will do the same through you to other people.
As you live a godly life, and take a stand for God’s Law in word and deed, the Spirit will convict the people around you of their sins. And when you open your mouth, telling them all that Jesus has done, His death and resurrection, the Spirit will move them to trust Jesus, to come alive by faith in Jesus.
And this will prove to be the constant struggle of the Church. From the day of His ascension until the day of His return, the people of God are striving to grow in faith and love. They are striving to spread the kingdom to the ends of the earth. By the power of the Holy Spirit it is happening in our lives, in our churches, and beyond.
Yet the day will come when the kingdom of God will spread across the globe in an instant, in the twinkling of an eye. And for that day we earnestly pray as well. Jesus Christ will reveal Himself to be the rightful King of the Universe, the undisputed ruler of heaven and earth. He will raise the dead, separate believers from unbelievers, take the righteous by faith to Himself and cast the unrighteous by unbelief into hell. The kingdom will have come in full.
You see that we pray for no small thing when we say those simple words: “Thy kingdom come!” We are asking for an increase of faith, love, and life. We plead, not merely for earthly riches, but for heavenly and eternal treasures. We are praying for resurrection from death and life everlasting.
And God promises to give it. He will not deny this prayer. On our own we might doubt, but not in Christ. Baptized into Jesus, covered with His blood, united into His family, we pray boldly as sons: “Thy kingdom come, now and forever!”