Almighty God Reveals the Inside Story of the Work of the Age of Law | Why God Worked in Israel in the Age of Law
The work that Jehovah did upon the Israelites established among humanity God’s earthly place of origin, which was also the sacred place where He was present. He confined His work to the people of Israel. At first, He did not work outside of Israel; instead, He chose a people He found suitable in order to restrict the scope of His work. Israel is the place where God created Adam and Eve, and out of the dust of that place Jehovah made man; this place became the base of His work on earth. The Israelites, who were the descendants of Noah and also the descendants of Adam, were the human foundation of Jehovah’s work on earth.
At this time, the significance, purpose, and phases of Jehovah’s work in Israel were to initiate His work on the whole earth, which, taking Israel as its center, gradually spread into the Gentile nations. This is the principle according to which He works throughout the universe—to establish a model and then broaden it until all people in the universe shall have received His gospel. … Not only this, but the work He began in Israel was meant so that other peoples and nations (who in fact were not separate from Israel, but rather had branched off from the Israelites, yet were still descended from Adam and Eve) might receive the gospel of Jehovah from Israel, so that all created beings in the universe might be able to revere Jehovah and hold Him to be great.
from “The Work in the Age of Law” in The Word Appears in the Flesh