The second book is extremely important because it provides a foundation for Reformed perspectives on human nature, especially the enslaved will.
By now, readers should have noted that Calvin follows the outline of the Apostles' Creed. God the Son is the focus of this portion of the work. Those with a background in churches that have difficulty making sense of the "old covenant" should find Calvin's thoughtful approach to the relationship between the Old and New Testaments fascinating.
Calvin develops his teaching on the prophetic, priestly, and royal offices of Christ here. Also note that he begins his discussion of soteriology here without a formal discussion of predestination.