How do we know God has fulfilled His promises to Israel?

In the Old Testament, God made specific promises to the nation of Israel regarding land, rest, and His presence among them. Joshua 21:43-45 confirms that God gave Israel all the land He promised, and they possessed it. However, with the advent of the New Covenant, the focus shifts from physical Israel to spiritual Israel. Under this covenant, true fulfillment lies in the spiritual realities that Christ accomplishes, where He brings together all nations into one people of God (Ephesians 2:14-16). This means the physical land promise has been spiritually fulfilled in Christ, who reigns over a heavenly kingdom, which is not contingent on ethnic identity but on faith in Him.