Religion is sometimes attacked as a source of ignorance and conflict. While all humans are subject to confirmation bias, perhaps the real danger is dogmatism, or the tendency to lay down principles as incontrovertibly true, without consideration of evidence or the opinions of others, especially when it leads to prejudice or violence. That condition may affect both the religious and the nonreligious.
 
Is Snoopy being “dogmatic”?
As this article points out, people who dogmatically hold to any topic without being able to consider other perspectives “typically pay a high price for their dogmatism. Not only do they alienate many people, but they actually imprison their own egos inside their figurative fortress of conviction.”