They serve some entertainment purpose. My problem with myths is that they brainwash people into strapping bombs to their chest so they can go defile their 72 virgins in the afterlife. They tell people being gay is a sin and they're going to burn in hell for all eternity. They tell people that someone died for their sins and that they're supposed to accept this as truth on no evidence whatsoever. The myths give god all of the credit for other people's good works, and tell them that they are worthless, and can do no good without "the" god of their faith. I feel this world could use a bit more reality, and could afford to lose some of its myths.
"That which can be asserted without evidence, can be dismissed without evidence." -Christopher Hitchens- My Hero