historicly religions where (and still to this day) used to control and influence people to follow a leaders belife / political idea. look around the world and you can see many examples
generally the programming that goes with a religion, like a comptuer virus, there is a secontion to spread it as hard as possible to others.
thats usually where the egotistical / arrogance / conviction comes from with people who follow a religion as they see people who are not in their group as a second class as a result.