Well, it depends. It depends on the culture who believe in the religion and the religion itself.
In the west for example, our main religion is Christian, however despite the fact Jesus says we must love both our friends and our enemy, during the age of the middle and dark ages, the west is known to have a violent history of killing each other due to different religion believe, even attacking people of none christian faith. (Even today, we still portrail Jesus as white male with blond hair blue eye, where in reality we all know Jesus is black.)
Today on the other hand, Muslim faith believe that you should only be allow to fight defensive warfare and you can only fight war when you have no choice (e.g. when the soivet union attack Afghanistan during the cold war or when Iraq attacked other nations during the golf war.) yet today, Osama Binladin, launch Sepetember Eleven attack upon the US.
However, in the East, Buddhism ideology played a major role in assisting Asia to be a first world region throughout most of its history. Mainly because Buddhism ideology believe in peace, freedom and equality and concept as stereotyping of any form is consider as a sin. it created a culture during the days of the king, where in exchange for the people to be loyal to their king, is for the king to be loyal to his people and the king work as a public servant (like a president) and in public interest.
Other religion are problematic itself, e.g. scientology is a typical example.