The Peace of Jerusalem

What did the LORD mean by using the name of Jerusalem [city of peace] in this Psalm? Why did God purpose that His House be in Jerusalem? Why did God set the people of Israel apart for His purpose? What makes a people a 'holy' people, a 'peculiar' people? How does all revolve around the coming of God's Christ, His Son? Why did the LORD bring His Glory through the least of all peoples? Why does all Spiritual blessing come through Christ? Do we ever stop 'coming to Christ'? What is Zion? Why do some stumble at God's Word? What was the significance of Mount Mariah as the place that God told Abraham that He would provide His Lamb?