What does it mean that the world is God's stage and He is bringing it to fruition?
It means God is sovereign and in control of every detail, ordering events according to His own timing. The world is His stage, and He is bringing it all to fruition in His own time, including Israel’s history and the lives of every child of God.
Les explains this in connection with God's sovereignty. He says God is in control of every jot and tittle of what takes place, not only in the life of Israel but also in the life of every child of God in particular. He cites the old cliche that the world is His stage, and indeed it is, with God bringing it all to fruition in His own time. In the surrounding discussion, this sovereignty is illustrated by Israel's time in Egypt—about 140 or 150 years of slave existence after Joseph died, though they had it super good in Goshen while Joseph was on the throne—and by Isaac's need to entreat the LORD for barren Rebekah for almost twenty years until the twins were born when Isaac was sixty.