"The Kingdom of God includes both His general sovereignty over the universe and His particular kingship over men who willfully acknowledge Him as King. Particularly the Kingdom is the realm of salvation into which men enter by trustful, childlike commitment to Jesus Christ. Christians ought to pray and to labor that the Kingdom may come and God's will be done on earth. The full consummation of the Kingdom awaits the return of Jesus Christ and the end of this age."
The kingdom of God is a huge topic because it could perhaps be thought of as the central theme of the whole of Scripture, if such a thing exists. Obviously Christ is the Person revealed by all Scripture, and who gives it its cohesion, but it is precisely the kingdom of God which Christ brings about by His coming. For this reason the BF&M section on the kingdom seems relatively short in one sense, but perhaps it is difficult to say too much more about such a huge scriptural theme in a summary statement in a confession or statement of faith.
As they stand I don't have a problem with this section's affirmations. The section acknowledges God's absolute sovereign kingship over all Creation as well as His covenant lordship over His people, which Christians should pray for an ever-greater expression of as more people bow the knee to Christ and enter His kingdom of light through faith in Him.
My only criticisms are aimed at the section's omissions. While my eschatology informs me here, I don't think people who hold to other orthodox views are exempt from considering these ideas as well.
First, while this section acknowledges God's kingship as Creator of all things, God's particular kingship over His own covenant people (those who "willfully acknowledge Him as King"), and even hints at the idea of God's covenant kingdom expanding over the earth and His will being done more and more, progressively as people enter by faith, nothing is explicitly said about Jesus' definitive, right-now, inaugurated kingship over all of heaven and earth (Matt. 28:18). This is not exactly the same idea as God's general right to rule all creation. It has to do with the redemptive-historical shift that has taken place with the Advent and work of Christ.
The omission of this category, as well as the de-emphasis on the next one of which I will speak, may be due to the prevalence of premillennial (and even, amazingly, sometimes still dispensational) eschatology in baptistic circles. Yet even many premillennialists--although perhaps especially those who follow the strong "already-not-yet" schemes like George Ladd's--can acknowledge that something definitive has happened with the completion of the work of Christ regarding the establishment of the kingdom of God on earth.
Scripture is actually very clear on this idea. One cannot read the New Testament without seeing how Jesus, by virtue of His death, resurrection, and ascension, has in a definitive and fundamental way laid claim to all of the earth and is King over it--and over all the people on earth--in a way that God was not King over it before (even though He has always been the Sovereign Creator King in the first sense of which we spoke). Matthew 28:18; Acts 2:36; and Ephesians 1:20-22 are a few examples. From a hermeneutical standpoint of receiving the full exegetical weight of the imminent time statements in the didactic portions bookending the rest of the book of Revelation, Rev. 11:15; 12:10 become relevant and demonstrative as well.
The coming of Christ was the apex of earthly history, bringing about definitively in His resurrection the very beginning of New Creation but also the full defeat in principle of all God's enemies, fundamentally sin, death, and Satan. Of course this has yet to be worked out fully in the world and consummated. But it is the definitive reality of Christ's victory that gives the Church great hope and confidence, fueling its missiological zeal. God has reclaimed the whole earth through Christ. He has become the king of the men of earth in a way which has not been a reality since before the Fall. Yahweh promised the king--and ultimately His Messianic Son--the nations in Psalm 2:8 if He would but ask for them. Well, the Son has asked for and received the very power which will enable this to happen (Acts 2:33), and the Church has been echoing this prayer for empowerment for its task ever since--and receiving such. The evidence is the conversion of people from many nations thus far, which brings me to my next point...
While this section of the BF&M mentions praying for the coming of the kingdom, it does not explicitly mention the progressive aspect of the establishment of Christ's kingdom. It speaks of Christ's kingdom of His followers, and it speaks about the day when that kingdom will be consummated--both very important ideas. But there is also, as two of Jesus' well-known kingdom parables (leaven and mustard seed) illustrate, a progressive, non-cataclysmic aspect to the establishment of His kingdom (contra many 1st-century Jewish apocalyptic expectations).
Again, I have a sneaking suspicion that widespread premillennialism in SBC circles accounts for this (minor) omission or de-emphasis. However, I wonder if a sort of "radical two-kingdom" or imbalanced "spirituality-of-the-church" type of missiological mindset is behind this as well (old Southern Presbyterians leaned in this direction at times as well). Baptists have typically held very strong notions of the "separation of church and state," and have avoided heavy involvement in social justice issues and politics as a main part of the Church' mission. It would certainly be wrong to swing all the way to the other side of the spectrum on this issue, minimizing evangelism and being preoccupied with social justice for its own sake, but a more robust missiology related to the cultural mandate could bring needed balance here in some quarters (this kind of a correction seems less needed today among Baptists than it was in the past couple of generations at least in America, by my limited perception of things).
We need to understand that the cultural mandate (the commands for human beings to steward the earth, harness its resources, bear fruit, and multiply, found in Genesis 1-2) is not done away with because of the Fall, much less because of the establishment of the "heavenly" or "spiritual" kingdom of Christ. Man's ability to fulfill the cultural mandate was ruined because of sin. Christ came to take away sin and its effects. Therefore it is part and parcel of salvation and of the ever-expanding (or, "ever-being-more-realized") kingdom of Christ that man is restored to his original capacity as image of God to rule over creation effectively as God's vice-rulers. Hebrews 2:5-8, connecting Psalm 8 (which is about man in general) to the victory of Christ specifically, demonstrates this dynamic.
This is why the Great Commission command to "disciple all nations" includes not only incorporating people into Christ/the Church (baptism), but also instruction in living as God's subjects in all of life by obeying His Law ("teaching them to observe all [Christ has] commanded...") As more and more people do this--and we see the beginning of that progressive process in the book of Acts and beyond, as reflected particularly in Paul's epistles--the Church and the gospel message it proclaims becomes the vehicle for the completion of the cultural mandate, reversing the curse and re-establishing (and one day consummating) God's rule on earth through man His covenant representative. This is why I sometimes refer to my postmillennial convictions more descriptively as "progressive representative dominion restoration." But that's neither here nor there.
In sum, my wish (whoever I am) would most importantly be to insert something explicit in this section of the BF&M about Christ's definitive, "already" Messianic kingship over all heaven and earth (even unbelievers), even though as Hebrews admits, we do not yet see all things subject to Him (Heb. 2:8) because we are awaiting the consummative completion of the earthly, progresive kingdom-building for which we pray in the Lord's prayer.
I believe one of the healthiest things for a Christian to do today, as well as for the Church, on a more cosmic scale, to do, is re-emphasize the definitive realities of positional sanctification (individual microcosm) and the inauguration of Christ's kingdom at His resurrection (global/macrocosm), and then on the basis of that foundation to work on bringing about more of the progressive aspects of sanctification and mission, with a hope for and ultimate view to the consummative, Last Day realities of glorification and the fullness of the kingdom. As many say today, gospel imperatives are based on gospel indicatives in the New Testament (especially in Paul). This is true for the Church and its Great Commission efforts as a whole as well.