Why do religious people say nonbelievers are blind?

I think it's really a cultural thing. Some people are surrounded by religion from birth, and the way people are raised in relation to religion can make them unable to understand others' beliefs. Not true in every case, however. Atheists and agnostis can be sensitive to one religious person's judgement, and make generalizations about all religious people. Not all believers think that about nonbelievers. I am agnostic and have plenty of religious friends- Christian, Muslim, Jewish, you name it. It's all about co-exisiting.