Hello Ron,
Firstly, the universe is a manifestation of God’s attribute ‘Extension’ which is one of the infinite attributes of God’s nature. God, Himself does not have a purpose which your friend is correct. If He lacks something God would not be God so He doesn’t lack anything. Regarding human nature, which is to exist and persist in his existence as long as possible. There is no free-will in man and he has no real purpose, for his purpose is only to survive. However, man has an intelligent potential; that is, to uncover his true nature which is his mind which has the power to come to clear ideas. Within man lies a dormant intelligence and once this intelligence is uncovered through the works and philosophy of Spinoza, then, it would possible that the mind of man can awaken and partake in God’s divine nature and intelligence.