when we enter the unique spiritual realm of the New Testament. For in the encounter with the Christ of the Gospels there is the assertion of a mighty living reality as inseparably bound up with the Old Testament past as pointing forward into the future. That which binds together indivisibly the two realms of the Old and New Testaments - different in externals though they may be - is the irruption of the Kingship of God into this world and its establishment here. This is the unitive fact because it rests on the action of the one and the same God in each case; that God who in promise and performance, in Gospel and Law, pursues one and the selfsame purpose, the building of his Kingdom. This is why the central message of the New Testament leads us back to the testimony of God in the old covenant.Eichrodt's powerful formulation here might be improved only in the understanding that, as Jesus said, the kingdom is "not of this world" - meaning not only that the kingdom includes the metaphysical beyond the physical, but meaning also that God's concept of kingship, as the ultimate concept of kingship, has been elevated to the extent that it includes, and more than includes - it operates with the foundational axioms of those notions - mercy, grace, love, agape, forgiveness - which are understood be the core of the Gospel.
Correctly Eichrodt writes about the building of the kingdom: it is built as God's Spirit pours out the gift of faith. The irruption of God's Kingship is the emergence of God's unearned love, His unmerited grace and mercy toward humans. The building of God's kingdom is, then, the deconstruction of power structures, meritocracies, as humanly understood.
Just as God called people to be His people - Abraham did not in any way earn God's favor, nor was he righteous or obedient prior to God's call - in the Old Testament, so in the New Testament it is "not because of our righteous deeds" (as Paul writes to Titus), but rather because of a unilateral giving impulse on God's part that His Kingdom is built.
