The Kingdom of God is not an earthly geographical kingdom, but the reign of God, predicted in the Old Testament and established through the death and resurrection of Jesus.
There is a great emphasis on the kingdom in the synoptic gospels, where it is described both as a present reality, as well as a future expectation. It is now, but not yet. The good news of the kingdom formed the centre of the preaching of Jesus (Mk 1:14-15), confirming the declaration of John the Baptist (Mt 3:2). Jesus showed that the future had broken into the present. The good news is that the eschatological blessings of salvation and life in the kingdom are now available to those who believe.
Jesus used parables to teach the true nature of the kingdom, to counter the popular Jewish expectations of a military kingdom to be established in Jerusalem. The kingdom was a mystery, which was revealed to the disciples, but hidden from the crowds, because of their hard hearts (Mk 4:11f). The kingdom is like a mustard seed, which started small, but grew very large (Mt 13:31f), or like a seed which grows and bears fruit at the final harvest (Mk 4:26ff), showing that the kingdom will grow until its consummation at the final judgement. The parable of the sower showed that the growth of the kingdom depended on the receptivity of the hearts of his listeners (Mk 4). Jesus demonstrated the arrival of the kingdom by signs and wonders, through healing (Mt 9:35), and especially by the casting out of demons, a sign that the strong man, Satan, had been bound (Mt 12:28f). He also taught that the full establishment of the kingdom was still in the future, when the Son of Man will come in the clouds (Mk 14:62). Before that time, the message of the kingdom had to break out from Israel to reach all nations (Mt 24:14).
The term 'the kingdom of heaven' is unique to Matthew’s Gospel. It appears to be synonymous with kingdom of God (Mt 19:23-24). Probably, as a Jew, Matthew was reluctant to use the holy name of God, so used 'heaven' instead.
This apparent tension between the present and future aspects of the kingdom has led to much scholarly controversy. Some scholars have emphasised the present reality of the kingdom at the expense of future consummation, especially C.H. Dodd’s teaching on realised eschatology. Others see a social gospel, emphasising kingdom values in society, rather than in personal salvation. Dispensationalists emphasise the future kingdom, claiming that Jesus offered the kingdom to the Jews, who rejected it.
In John’s gospel, instead of eschatology breaking into the present seen in the synoptics, the life of above is made available to life below. The emphasis is on eternal life, rather than the kingdom. However, Jesus told Nicodemus that he could only see the kingdom by being born from above (or again) (3:3), thus linking the kingdom with new life of the Spirit. Later Jesus confused Pilate by saying that his kingdom was not of this world (18:36).
In the book of Acts, the disciples proclaimed the kingdom in their preaching. In his Pentecost sermon, Peter proclaimed that Jesus the Messiah had suffered and was now exalted at the right hand of God, on the heavenly throne of David (Acts 2:30-36). Paul argued persuasively about the kingdom in Ephesus, so all residents heard the word of the Lord (19:8-10), later describing it as the good news of God’s grace (20:24-25).
Although Paul does not mention it many times in his letters, the arrival of kingdom is implied in his writing. We now live in the kingdom and are expected to behave accordingly (1 Thess 2:12). Jesus will hand the eschatological kingdom to the Father at his second coming, but for now he must reign until he has put all enemies under his feet (1 Cor 15:24ff), again showing the kingdom as a present reality with a future consummation.
The writer of Hebrews mostly emphasises the humanity and the earthly sacrifice of Jesus, rather than the kingdom. However, he describes the future kingdom as unshakeable city to come (12:28, 13:14), when compared with the instability on earth.
The kingdom is not mentioned much in the general epistles. Peter draws on the description of Israel as a priestly kingdom and holy nation (Ex 19:6) to describe the believers as a royal priesthood (1 Pet 2:9). He emphasises the future aspect of the kingdom when he describes the entry into the eternal kingdom provided for the believers (2 Pet 2:11).
The book of Revelation looks forward to the consummation of the kingdom in order to encourage believers currently facing persecution and martyrdom. God is described as “the one seated on the throne” (4:2), and the saints are made to be a kingdom of priests serving God (1:6), sharing the kingdom (1:9). All forces of evil led by the dragon, Satan, will ultimately be cast into the lake of fire (Rev 20:10). A great debate rages over the interpretation of the millennium when the saints will rule with Christ (Rev 20:1-6). A pre-millennial interpretation expects Christ to return and establish an earthly kingdom for 1000 years. Dispensationalists expect this to be a Jewish kingdom in Israel. The amillennial view does not expect this physical kingdom, but sees the 1000 years as symbolic of the current age of the church when the saints or the martyrs share in the rule of Christ.
Through church history, theologians have argued about the relationship between the kingdom and the church. The Roman Catholic view, taught by Augustine, identified the kingdom with the Catholic church, implying that salvation was impossible outside the church. The Reformers emphasised the invisible kingdom made up of true believers. In the New Testament, the church is not identified as the kingdom but as the people of God who have received the word and who will inherit the kingdom in the future.
D. Guthrie. New Testament Theology. IVP 1981. Pages 409-431.
G.E. Ladd. A Theology of the New Testament. Eerdmans 1974.
G.E. Ladd: Kingdom of God, in International Standard Bible Encyclopaedia (ISBE). ed. GW Bromiley. Eerdmans 1986
L. Morris. New Testament Theology. Zondervan 1986.
H.N. Ridderbos: Kingdom of God, Kingdom of heaven, in Illustrated Bible Dictionary. ed. JD Douglas. IVP 1986
G. Vos. Biblical Theology. Banner of Truth 1975. Pages 375-387.