Since being God's chosen people is not a DNA/Ethnic thing, it is about faith/obedience. Therefore, the promises made to God's people in the Old Testament are still valid and true, but you are missing who the recipients are of said promises. The recipients are those of faith who obey God. It's same then as it is now. That is why Paul writes in Galatians 3:7 "know then that it is those of faith who are the sons of Abraham." The Church is true Israel. Additionally you misunderstand the fulfillment of the covenants. They find their fulfillment in Christ. The promise to Abraham for descendants as numerous as the stars is ultimately fulfilled in the Gentiles being included in God's people (Ephesians 3:3-6). The promise for his descendants to a blessing to all nations is also fulfilled in Jesus via the inclusion of the Gentiles (Romans 11:17). And the promise for Land is fulfilled in Christ as well (John 14:3). You are missing the recipients and misunderstanding how the promises of the Old Testament are fulfilled.
"Be a listener only, keep within yourself, and endeavor to establish with yourself the habit of silence, especially on politics." -Thomas Jefferson