Immutability does not mean that God is static or inert, nor does it mean that He does not act distinctly in time or possess true affections. God is impassible—not in the sense that he is devoid of true feeling or has no affections but in the sense that His emotions are active and deliberate expressions of His holy dispositions, not (as is often the case with human emotions) involuntary passions by which He is driven.
John MacArthur