My first thought is that, despite superficial and obscured commonalities with other "dying"/"rising" gods (and they are often superficial and obscured), that the Gospels
purport to be history. So, if we want to be consistent in how we treat both Genesis and the Resurrection, it seems as if one must interpret Genesis, not in light of preexisting or contemporaneous mythologies, but in light of what the text itself purports to be. In that respect, commonalities with any other culture are ultimately irrelevant, and we must take the holy writ as it presents itself. So the complicated "cosmogonic" questions would seem to boil down to the rather old-school, "What is the "genre" of Genesis 1?" debate.