When was Israel a separated people in the Old Testament?
Israel was a separated people throughout the Old Testament whenever they maintained knowledge of God and His word. They lost that separation when they fell into idolatry and unbelief, and then God's judgment fell. God had mandated they stay separated from the Gentiles, as seen when Balaam's counsel led to seduction and 23,000 died.
Les teaches that Israel's separation was not due to bigotry or pride; God had mandated that they stay separated from the Gentiles. All the way up through the Old Testament, any time they had a knowledge of God and His word, Israel was a separated people. But when they went so far down into idolatry and lost belief in God, they lost that separation, and as soon as they did, God's judgment fell. A key example is Balaam the false prophet. Balak, king of Moab, brought him to curse Israel because he knew he couldn't defeat them militarily—there were too many. He couldn't curse them because God wouldn't let him. So Balaam had a satanically inspired thought: have the Moabites put their prettiest girls out to seduce the Jewish young men. It worked. God let judgment fall, and 23,000 Jews had to be put to death because they had lost their separated character. Les also points to Acts 22, where Paul's mention of being sent to the Gentiles caused a riot, showing how seriously the Jewish people took that separation.