To understand the Kingdom of God, we must understand the biblical meaning of the word, "kingdom." The archaic definition from Webster's dictionary gives us a clue. "The rank, quality, state, or attributes of a king; royal authority; dominion; monarchy; kingship. The primary meaning of both the Hebrew Old Testament word and the Greek New Testament word translated "kingdom" is the rank, authority and sovereignty exercised by a king. We have already ascertained that the Gospel of the Kingdom (Matthew 24:14) meant the Gospel of the Kingdom of God or the Kingdom of Heaven. Now we are ascertaining that, first of all, a kingdom is the authority to rule, the sovereignty of the king. So when it is written in Ezra 8:1 of the return from Babylon "in the kingdom" of Artaxerxes, it refers to his reign. Likewise, when the Scriptures refer to God's Kingdom, it refers to His reign, His rule, His sovereignty and not the realm in which it is exercised. (George Ladd, The Gospel of the Kingdom, [Wm. B. Erdmans, Grand Rapids, 1959] 20).
In Hebrew poetic expression, God's Kingdom is also His power. (Psalm 145:11). "Thy kingdom is an everlasting kingdom, and thy dominion endures throughout all generations." (Psalm 145:13) It is God's rule which is everlasting, not the realm of His rule, for the Scriptures also declare that this heaven and this earth will pass away. (Mark 13:31) So when Jesus said that we must "receive the kingdom of God" as little children, (Mark 10:15) He wasn't speaking about receiving the church, or heaven, but God's rule. So here we begin to see a condition of the Kingdom: to enter the future rule of the Kingdom, one must submit, in complete trust, to God's rule in the here and now.
How many times have you heard it said at a funeral, "Well, so-and-so is in a better place now"? For that to be true, so-and-so had better have already submitted to the rule of God in his former life. It is not written for nothing, "Seek first His kingdom and His righteousness." (Matthew 6:33) When we pray, "Thy kingdom come," we are not praying for heaven to come to earth, really. Apart from the reign of God, heaven is meaningless, so we pray, "Thy kingdom come, thy will be done on earth as it is in heaven." (Matthew 6:10).
Now we've dealt with the primary meaning of the word "kingdom," but let's face it; a reign without a realm in which it is exercised is meaningless. So we find that the Kingdom of god is also a realm in which God's Kingdom may be experienced. In this regard, the Bible sometimes speaks of the Kingdom as a realm to be entered at the present; sometimes as though it were future. In passages such as Matthew 7:21; Mark 9:47, 10:23, 14:25 the Kingdom is equivalent to that aspect of eternal life which will be experienced only after the Second Coming of Christ. Other passages, such as Luke 16:16, 11:52; Matthew 21:31, the Kingdom is spoken of as being present, capable of being entered now.
So we are faced made up of three facts: 1) Some passages of Scripture refer to God's Kingdom as His reign; 2) Some passages refer to it as the realm into which we may now enter and experience blessings; 3) Others refer to a future realm which will come only with the return of Christ, into which we will enter and experience the fullness of His reign. So, the Scriptures must be studied to determine by context which meaning is correct for the particular passage. "Be diligent to present yourself approved to God, a worker who does not need to be ashamed, rightly dividing the word of truth." (2 Timothy 2:15)
Fundamentally, the Kingdom of God is God's sovereign reign; but God's reign expresses itself in different stages throughout redemptive history. On occasion, God has entered human history and has abruptly changed it's course (the flood, the exodus). He has also entered human history and changed human destiny, but the manner of change has been much quieter, although no less real. I'm speaking here of the word becoming flesh and dwelling among us, speaking to us, and expressing in human form the image of God. (John 1:14; Hebrews 1:1-3) Thus man has been able to enter the kingdom of God at various stages of its manifestation, where they experience today, enjoying in part but in reality, the blessings of God's reign, while they await the fullness of those blessings to manifest when Jesus returns as King of Kings.
So when you pray, "Thy kingdom come, Thy will be done on earth as it is in heaven," pray with thankful confidence that His Kingdom is coming, and it will fill the whole earth. But when you pray that, also ask that God's will be done in the here and now (in you, in your family, in your church, town, state, country and the world). The church especially ought to be a fellowship of people among whom God's will is being done all the time. Our lives, our churches should be a sneak preview of the Kingdom of God.
"Therefore, brethren, be even more diligent to make your calling and election sure, for if you do these things you will never stumble; for so an entrance will be supplied to you abundantly into the everlasting kingdom of our Lord and Savior Jesus Christ." (2 Peter 1:10-11)
