That's a whole other can of worms though.
From the view of studying comparative mythology, of course it's easy to see the parallels between the stories. But a committed believer of a faith may take one of three routes if shown the comparisons:
A: "All of those stories are fictional myths from dead cultures so their similarity is coincidence and doesn't apply to the story from my faith, which is the truth. Gilgamesh and the Flood did not happen. Noah and the Flood did happen."
B: "Since these cultures' stories came before mine, the comparison is proof that the event did occur in the past. But they are distorted versions of mine, the true story. Someone older said that Gilgamesh and the Flood happened, therefore Noah and the Flood must have happened, but Noah is the truth of what happened."
C: "All of these stories are interesting metaphors and none of them literally happened, but we take meaning from them. Neither Gilgamesh nor Noah happened."
C can be agreed by both mythologists and believers.