In chapter three, Cremer continues his summary of the apostolic witness to Jesus Christ. The focal point of this chapter is on the meaning of Jesus' proclamation of "the kingdom of God." Recall that for Harnack this was the first of his three-point summary of the gospel as he understood it, "the kingdom of God and its coming." But his understanding of the kingdom of God was centered on the Fatherhood of God in a universalistic and non-soteriological sense. All humans are God's children. The kingdom of God is the religious experience of knowing God as Father, an experience realized first and foremost in Jesus' own relationship with God, a relationship that is not ontologically distinct from ours.
Cremer understands the teaching of Jesus concerning the kingdom of God as recorded in the Synoptic Gospels very differently. For him, the kingdom of God is to be understood first as the fulfillment of the promises of Israel's redemption, and, as such, it focuses on the Fatherhood of God not in a universalistic sense but in relation to those whom he redeems.
Jesus called God Father because He did the deed of redemption for which Israel waited. He is the Father of Jesus because Jesus is His Son, whom He has chosen to execute His redemption; He is Israel's Father because Israel is the object of redemption promised, and He is the Father of all those to whom He sends the redemption. With the redemption He proves that He has not forgotten His people, but interests Himself in them, shows His power and establishes His Kingdom among them. God's Kingdom and God's name of Father belong together. God's kingdom takes its name not from the obedience of the citizens of a kingdom, but from God's deed of redemption. (p. 50)
Harnack is right to interpret the kingdom of God in light of the Fatherhood of God. But he is wrong to take the latter concept and divorce it from the soteric realities of redemption accomplished (the cross and resurrection) and applied (the forgiveness of sins).
Furthermore, Harnack misses the vast ontological difference between Jesus' relationship to His Father, and our relationship to God as Father through Christ:
One can but feel that there is a peculiar meaning in which Jesus says Father in addressing God or in speaking of God. He speaks of Him as Father, who has called Himself Israel's Father, and who has called Israel His son, His first-born, and whom Israel also addresses as Father in its devoutest prayers. Jesus says "the Father," "your Father," "My Father," but never "our Father," except where he tells the disciples how to pray. The actual fulfilment of the promises is connected with Jesus; where Jesus is and only where He is there is God's Kingdom; therefore He says Father as no one else can say it. (pp. 50-51)
What, then, is meaning of Jesus' proclamation of the kingdom of God? It is the proclamation of God's act of redemption, through God's judgment on human sin in the person of Christ on the cross, resulting in the forgiveness of sins:
The Kingdom of God, for which He came, is the same at the end of His career as in the beginning. It represents in His earlier as in His later teaching a world-condition brought about by the righteous judgment of God the Father, in which His own have peace and freedom from all distress through the forgiveness of their sins. Jesus proclaims this Kingdom, He brings in this Kingdom; where He is, there is this Kingdom. (p. 52)
Cremer points to several critical moments at the end of Jesus' earthly life to demonstrate that the kingdom of God has this redemptive focus on the forgiveness of sins. In his parable of the wicked husbandmen, he said to Israel, "The kingdom of God will be taken away from you and given to a people producing its fruits" (Matt 21:43 ESV). Then, a few days later, at the last supper with his disciples, he said, "This is my body ... this is the blood of the covenant, which is poured out for many for the forgiveness of sins," followed immediately by another reference to the kingdom (Matt 25:26-29). Then, again, when the dying thief prayed, "Jesus, remember me when you come into your kingdom," Jesus replied, "Truly, I say to you, today you will be with me in Paradise" (Luke 23:42-43). "Thus, dying, He endorses still the Gospel which He has preached" (p. 59). The gospel of the kingdom is thus the gospel of the forgiveness of sins by the blood of Christ, a gospel of free grace for sinners.
It is God who through this Kingdom, in the omnipotence of His love, fulfils His promises, not for and on the righteous, not for those who are whole, but for and on sinners, for and on such sinners as she was of whom it is recorded that He knew not "who and what manner of woman this is which toucheth Him." For them Jesus was sent from God, for them He brings the grace of God, which they need; such as these will He comfort and revive. To Him should they come, in Him should they believe. He is not subject, but object of religion. (p. 60).
These were sinners' souls, in whom Jesus had an interest, as He shows when He interests Himself in the paralytic and the publican. It is not, as Wellhausen says, that "His predilection for sinners sometimes seems to go too far ...." Rather what Paul attests later is true: "Where sin abounded, grace did abound more exceedingly." Jesus has proved this, and thus made Himself the center of attraction to sinners to assure the most miserable of the miserable that the Kingdom of God is at hand, and that He is the King of this Kingdom, chosen of God. (pp. 60-61)
Oh what a wonderful Savior Jesus is! His predilection for sinners did not go "too far"! He came precisely to seek and to save the lost, the miserable, and the ungodly. That is why the "gospel of the kingdom" is glad and joyful news for sinners (Matt 4:23; 9:35; 24:14; Mark 1:14-15; Luke 4:18, 43; 7:22; 8:1; 9:6; 16:16; Acts 8:12; 28:23, 31). It is not a message stating that a dread king is coming to whom you must yield obedience before it is too late. The gospel of the kingdom is the good news of the free pardon of all our sins through the person of the King of the Kingdom, that is, Jesus the Christ, whose Messiahship is defined in terms of the shameful cross (Mark 8:29 ["You are the Christ"] compared with vv 31ff [the passion predictions]) that he bore in our place and for our sins.