John the Baptist appeared in Israel with the message: `` Repent: for the kingdom of heaven is at hand'' (Matt 4:17, cf. 3:2) John, Jesus and the Apostles use this idiom of the kingdom to express the message of salvation to contemporary Judaism, on the one hand because apparently it was a well known expression in the late jewish apocalyptic writings and thus a known concept and, on the other hand because the ideas they wished to express thereby were deeply anchored in the Old Testament revelation of God and expectation of faith.1.35
Although the expression `the kingdom of heaven' or `the kingdom of God' does not appear at all in the Old Testament the idea that is expressed by it certainly does. ``What Israel lived and experienced in its history as the nation of the special revelation, was already a form of the kingdom of God realized in the theocratic life around the law and under the rule of God, while the earthly, national king was his anointed; and at the same time it was expectation for the future, because the underlying principle of the confession that God is king in the present, was the expectation that he would be king in the future in an intensified and eschatological sense.''1.36
Jesus states: ``The time is fulfilled and the kingdom of God is at hand: repent ye and believe the gospel'' (Mk 1:15). The opening words `the time is fulfilled' speak of something that has found its completion, its final stage in the present. This fulfillment refers to the Old Testament expectation. In Christ the kingdom of God has come. The nature of this kingdom is indicated by Jesus when He states: ``If I cast out devils by the Spirit of God, then the kingdom of God has come upon you'' (Matt. 12:28, Luke 11:20), and ``I beheld Satan as lightning fall from heaven'' (Luke 10:18). This indicates Christ's victory over the demons. The nature of the kingdom is also expressed by the fact that Jesus' preaching of the kingdom and his miracles are repeatedly mentioned in the same breath (eg. Matt. 4:23; 9:35) Christ's healing of the sick and bringing to life of the dead (as well as his own resurrection) express his victory over death. Finally the essence of this kingdom is referred to as the preaching of the gospel - ``The law and the prophets were until John: since that time the Good News of the kingdom of God is preached'' (Luke 16:16). The good news that is preached is the forgiveness of sins. The kingdom of God is salvation from sin, death and the demons. The kingdom of God is salvation in Christ.1.37