Tell me why you worship a God that killed everybody because they didn't worship him?
I'm pretty sure this is meant to be a reference to the deluge.
The reason for the deluge wasn't that humans didn't worship God, but rather that Humans were wicked and evil. While not everyone supports the death penalty, practically everyone agrees that wicked and evil people should be punished in some way, and in most cases fairly severely, such as being locked up in a cell or being forced to do hard work.