Christian zionism or Israel theology

Why did God choose the Israelites to be his people, and why did He give them a land? Which Covenant made Israel God's people? What is the consequence if God's people break the Sinai Covenant? Can an everlasting promise or covenant be withdrawn or cease to exist? If so, why? If not, why not? If the Israelites are not God's people anymore, do they have a Biblical right to live in the country where their ancestors lived? Does this land belong to Israel? What does the New Covenant mean for Israel? What was the mission of the Jewish Messiah? Did the Jewish Messiah come to undo the fall in paradise, overcome death, overcome Satan and establish the Kingdom of God, or was his mission to graft the Gentiles on Israel and to revive old times to make an earthly kingdom of Jews? Who is the real enemy of God's people? Satan and his angels or flesh and blood Palestinians, Iranians and Muslims? The author is a teacher and an elder in an Evangelical Church in the Netherlands. He wrote books about pastorate, spiritual warfare, the end-time, birth-sin, Israel, the Church and Islam.