Why did God's plan to use Israel to reach the nations fail?
God's plan failed because Israel did not believe it. Although God in His sovereignty intended to use Israel to bring the knowledge of the God of Abraham, Isaac, and Jacob to the ungodly nations, Israel's unbelief prevented that purpose from being fulfilled.
Les explains that everything from Genesis chapter 12 and the Abrahamic Covenant dealt with the nation of Israel. God gave them the Law and the Temple with the idea that one day He would funnel them back into that filthy, ungodly river of humanity and bring them a knowledge of the God of Abraham, Isaac, and Jacob. Les says that was the noble plan of God in His sovereignty, but it didn't work because Israel didn't believe it. From there, the timeline moves from 2000 years to the next major Old Testament event at 1000 B.C., the appearance of King David, Solomon, and the building of the first Temple.