Who was the deity Mammon?
I was shocked to find that Mammon, "son of the devil" in the movie Constantine was actually based off of a real deity. Was he the son of the devil as well? Does he bear any resemblance of the Egyptian god Ammon? (Amon-Ra)
Mammon as a deity was not originally a biblical concept, and in the Old Testament seemed to be simply a reference to treasure that was acquired illegally or immorally, so mammon carried the connotation of riches or wealth obtained wrongfully.
In the New Testament, however, in Luke 16:9 and 11, we read "Make to yourselves friends/of the mammon of unrighteousness" and "ye have not been faithful/ in the unrighteous mammon," both of which verses essentially create a personification of mammon.
Later, St. Jerome in his Commentary on Matthew, also personifies mammon in his observation that "Ye cannot serve God and Mammon." The fact that he capitalizes both God and Mammon lends weight to the belief that, at least to the early church fathers, the concept of mammon as ill-gotten riches had become a fully-personified God. This personification carried through to the Middle Ages when Peter Lombard described Mammon as "Mammon is the nave of a devil." Later in the Middle Ages, one of the primary religious poems of Medieval English literature, Piers Plowman, includes Mammon in a list of deities.
There does not appear to be any biblical connection with an Egyptian deity, but there is sufficient biblical commentary and literary use to indicate that Mammon was seen as a deity and not just a concept.