I'm reading through J.J. Collins and A.Y. Collins King and Messiah as Son of God and am enjoying it very much (I wish I had this book a year or two ago!). I've always enjoyed John Collins' work on Daniel and the rise of messianism. This book looks more explicity at the links between divinity and messianism.
In the opening chapter, John Collins discusses notions of divine kingship in the ANE. He notes that scholars have shrunk back from earlier claims that these monarchies (Egypt, Hittite, Mesopotamia, etc.) regarded their kings as incarnations of gods. Collins cites two scholars to counter this view: (1) Silverman: "A pharaoh might be: named as a god in a monumental historical text, called the son of a deity in an epithet on a statue in a temple, hailed as the living image of god in a secular inscriptions, described as a fallible mortal in a historical or literary text, or referred to simply his personal name in a letter"; and (2) Leprohon: "The evidence shows that the living pharaoh was not, as was once thought, divine in nature or a god incarnate on earth. Rather, we should think of him as a human recpient of a divine office. Any individual king was a transitory figure, while kingship was eternal".
I think two implications flow from this: (1) The divine-language used to describe kings in the OT (e.g. Psalm 45 "elohim"; Isaiah 9 "immanuel") are part of the ANE culture that is being tapped into and the king is praised in exalted terms, though still human and still evidently subject to God (see esp. the wider context of Ps 45). The Israelite/Judahite king was never an object of veneration in the cultus, but rather functioned as its chief custodian. (2) In Genesis 1.26-27, when humans are said to be in the "image of God", theologians argue over what the "image" precisely is: moral, psychological, relational, etc. But since "image of god" was used quite often to describe ANE kings, it means perhaps no more than humanity is royal in God's eyes and is charged with the delegated divine function of ruling over creation.
