http://www.non-religious.com/faith.html Faith - Belief that does not rest on logical proof or material evidence.
Religious faith is simply unjustified belief in matters such as life after death, or god, in the absence of tangible evidence. There are many detrimental results of religious faith:
Irrational thought instead of logic, and people giving no consideration to the possibility that they are wrong.
Intolerance of people who hold other beliefs, or no religious beliefs.
Using different moral guidelines, or not using moral guidelines, in the treatment of people outside their faith.
Sanctioning people, or countries, of other faiths, thereby making society less productive.
Faith often sparks violence between groups; one just needs to look at history to find countless examples of wars and conflicts where faith has been a contributing factor. Sam Harris, in his book "The End of Faith," argues that in the presence of weapons of mass destruction we cannot expect to survive our religious differences indefinitely. He states, "We have simply lost the right to our myths." Rationality, instead of religion, needs to be applied to ethical issues on both the local and global levels.