In 14:22 we see that Paul and Barnabas told the disciples that “through many tribulations we must enter into the kingdom of God.” Many think that the kingdom of God is merely a sphere where God may rule over people as the King. According to this understanding, the kingdom of God is simply a realm where God rules over His people. I do not say that this understanding is wrong, but it is superficial and natural.
The kingdom of God was a main subject of the apostles’ preaching in Acts (8:12; 19:8; 20:25; 28:23, 31). It is not a material kingdom visible to human sight, but a kingdom of the divine life. It is the spreading of Christ as life to His believers to form a realm in which God rules in His life.
In the Life-study of Mark we have pointed out that the kingdom of God is the Savior Himself (Luke 17:21) as the seed of life sown into His believers, God’s chosen people (Mark 4:3, 26), and developing into a realm in which God may rule as His kingdom in His divine life. Its entrance is regeneration (John 3:5), and its development is the believers’ growth in the divine life (2 Pet. 1:3-11). It is the church life today, in which the faithful believers live (Rom. 14:17), and it will develop into the coming kingdom as an inheritance reward (Gal. 5:21; Eph. 5:5) to the overcoming saints in the millennium (Rev. 20:4, 6). Eventually, it will consummate in the New Jerusalem as the eternal kingdom of God, an eternal realm of the eternal blessing of God’s eternal life for all God’s redeemed to enjoy in the new heaven and new earth for eternity (Rev. 21:1-4; 22:1-5, 14).
In Acts 14:22 Paul entreated the believers who were continuing in the faith to realize that through many tribulations we must enter into the kingdom of God. Do you think that Paul regarded the kingdom of God only as a realm where God’s people are under His ruling, and that to enter into this realm we must pass through tribulation? Paul may have had the thought that the kingdom of God is a realm in which God rules over His people, but this certainly was not his main thought concerning the kingdom of God. We need to remember that Paul was entreating disciples who were somewhat advanced. They were continuing not only in the grace of God but also in the faith. The charge to continue in the faith is both deeper and higher than that to continue in the grace. Therefore, those whom Paul was entreating in 14:22 were somewhat learned in divine things. In telling them that they must enter the kingdom of God through much tribulation, Paul certainly regarded the kingdom as something more than an objective realm in which God rules as the King.
What, then, was Paul’s main thought concerning the kingdom of God? If we would know this, we need to realize that according to the New Testament the kingdom of God is not a visible, material realm. Actually, the kingdom of God is a Person, the Lord Jesus Christ Himself. When He was questioned by the Pharisees about the kingdom, “He answered them and said, The kingdom of God does not come with observation; nor will they say, Look, here! Or, There! For behold, the kingdom of God is among you” (Luke 17:20-21). As the context proves, the kingdom of God is the Savior Himself, who was among the Pharisees. Wherever the Savior is, there is the kingdom of God. This was the reason He could say that the kingdom was among the Pharisees. As the Lord’s word in Luke 17:20 indicates, this kingdom does not come with observation; that is, it is spiritual, not material and visible.
In the four Gospels the Lord Jesus sowed Himself as the seed of the kingdom into His disciples. The development of this kingdom seed begins in Acts and continues in all the Epistles. This development reaches its consummation—the harvest—in the book of Revelation. According to the Lord’s word and Paul’s understanding, the kingdom of God is not a material realm. Rather, the kingdom is spiritual, divine, and even personal. The kingdom is Christ as the seed sown into the hearts of His chosen people. Our hearts are the soil into which the kingdom seed is sown and in which this seed develops. As we have pointed out, the seed of the kingdom is sown in the Gospels, it develops in Acts and the Epistles, and it consummates with the harvest in Revelation. This is the proper definition of the kingdom of God.