Well, The belief that the entire earth was covered completely with water for over a year, and yet plant life still lives, and there is no evidence of it to be found, is quite illogical... (Also if it was covered with salt water, all freshwater fish would be dead, and if it was covered with fresh water, all saltwater fish would be dead... and before you ask, there is no perfect balance of salt/fresh water, otherwise it would be used in fish tanks... ir must be one or the other.)
The belief that the whole solar system stood still for a day, so that some guy could finish killing people... and yet there is no evidence of it to be found, is quite illogical...
The belief that all the animals, will eat grass and will stop killing each other, even though they very obviously are incapable of making such a switch. (What about that wasp, who has to lay its eggs inside a caterpiller to reproduce? Or the vampire bat, or the gnats and ticks... they have no way of surviving on plants.) That's quite illogical. And would require and immense change of anatomy for 75% of everything on earth.
The belief that someone, an invisible and indetectible spirit creature, that has the whole world in his power, who claims that humans would be better off without god, would deliberatly cause problems for them, thus ruining his whole arguement, is quite illogical.
I should also point out that humans were not designed to live forever, that's why our spines slowly get worse the longer we live, we only have two rows of teeth, and why would we have an immune system, and sneeze reflexes if we weren't supposed to get sick?
LtCmd.Lore