Despite Adam’s failure to keep covenant in Eden, which introduced a division between the created order and the heavenly kingdom, God did not leave humanity without any hope. Instead, He promised to bring about the restoration of His kingdom through the defeat of Satan (Gen. 3:15). This initial gospel of the kingdom was later proclaimed more fully as it was revealed that the kingdom’s arrival would mean eternal life for its citizens and the renewal of all creation (Isa. 25:1–9). Becoming a righteous citizen in this kingdom is possible through faith alone, a faith that trusts the divine promises even when it is hardest to do so (Hab. 2:4).
The coming of the kingdom and its renewal of creation would accompany the restoration of the exiled Israelites to their land (Deut. 30:1–10; Zech. 14). Moreover, the dead would rise (Dan. 12:2) and Gentiles would pour into the kingdom (Isa. 19:16–25; Micah 4:1–5). Thus, the ancient Jews were saddened when, after returning to Canaan from Persia, they did not see the kingdom’s glories immediately.
But God was being merciful, choosing to bring His kingdom in stages and not all at once, giving the world time to turn to Him. So Jesus came preaching the gospel of the kingdom, proclaiming that the kingdom of God is both a present and future reality, and that all who repent and trust in Him in the present are declared righteous citizens, guaranteed to enjoy all the kingdom’s benefits in its future consummation (Mark 4:30–32; John 3:16). That Jesus is the agent who brings the kingdom was confirmed in the signs of restoration in His ministry. His miracles and resurrection were a foretaste of the promised new creation, proving that He will finish what He started.
Since the days of Jesus, the future kingdom has been brought into the present. And because the kingdom is here, it is now time for the Gentiles to be saved, and so apostles like Paul heeded the call to bring the gospel message to all the earth. God’s grace is seen clearly in the extension of the kingdom to the Gentiles, for even though those who are not physical descendants of Abraham are foreigners to the Lord’s covenants, He does not require anything more of them for citizenship in the kingdom than He does of those who already have the oracles of God. In other words, as Romans 1:16–17 says, both Jews and Gentiles enter the kingdom by faith alone.