God is a King. His kingdom is glorious, majestic, everlasting, Psa. 145:1, 11-13; Dan. 4:3. It is universal, “His kingdom ruleth over all,” from a throne in the heavens, Psa. 103:19. Mentioned some 70 times in the NT, the kingdom of God was the subject of Christ’s post-resurrection ministry, Acts 1:3, and that of the apostles, Acts 8:12; 19:8. God’s natural laws govern the world of nature; His written laws were given to govern and control men.
God’s kingdom includes things that are seen: “all the earth,” Psa. 47:7; material things as well as living creatures, Psa. 104; men and their rulers, Dan. 4:17. Its visible establishment on the earth was announced at Christ’s first coming, Mark 1:15. It will be set up at His return, Rev. 12:10.
The kingdom also includes things invisible. Believers enter it at the new birth; the unsaved cannot see it, John 3:3, 5. Characterized by righteousness, peace, and joy, Rom. 14:17, it is not inherited by flesh and blood, 1 Cor. 15:50.
Angels are a part of God’s kingdom, Psa. 103:20-22. Satan and demons are answerable to it, Isa. 24:21, 22; Rev. 20:1-3. Men are to seek it, Matt. 6:33. Believers are to be worthy of it, 2 Thess. 1:4, 5. It is never identified with the church in Scripture, nor are men anywhere told to build the kingdom.
William Evans, The Great Doctrines of the Bible, (Chicago: Bible Institute Colportage Assoc., 1912), WORDsearch CROSS e-book, 302.