Though I am as skeptical of religious fervor as any other Deist/Objectivist, Watson misses the mark completely here. The wars and bigotry stem from the belief that one's own particular variant of ethical monotheism is the One True Way, and that all who oppose you are heretics and deserve to be put to the sword. "The idea that our life and ethical conduct on Earth determines how we will go into the next world" serves as a moderating influence to that impulse, and has prevented wars and bigotry in societies where it has been adopted.
Yep. In this sense, it is a continuation of polytheism, with a personal, tribal or national "god" protecting the faction in its battles. The idea that my god and my enemy's god are One and the Same is a true departure from historical thinking.
SD