Depends on the arena I come across them in as to how I feel about them.
I am an Agnostic Atheist.
I have some very religious friends, who I get on well with, can discuss almost anything with, including religion. This is because we respect each others differences, and in discussions on religion etc seek to learn from the experience.
To them and many others in their position - their particular world view is the only legitimate one - to them - and they respect that they feel this way, but many others don't. I guess they may feel concern or sadness that we others may not end up the same place they will after this life.
HOWEVER, those I come across online are usually less respectful, more assertive/aggressive with their stance. Some are downright disrespectful in their interactions with people who are not sharing in their world view. I think they may have come down with a small case of the "anonymity power trip" and like the fact that they can be more assertive than they are IRL, without the same consequences eg being responsible for the outcome of their actions (if you don't know who they are, you can't hold them responsible for your...(insert negative emotion they've caused) etc). There is no need to be disrespectful - it actually takes away from what you are trying to say. The need to be disrespectful makes me feel sorry for them actually - not angry or annoyed - but sad - they can't see they are doing themselves a disservice.
THEN there are those who like to legislate the lives of other people based on the God/s they worship - be is ISIS, politicians using their own religion to tell others how they should live their lives, etc. These people annoy me.
I'm more than happy to have a respectful conversation with someone who is the complete opposite of myself in a religious sense, and would love to do so with anyone who is willing to try this with me - as long as we can be respectful. (and please contact me if you wish to do this... I actually enjoy the learning experience)
I understand it's a difficult ask to have someone look at a world view different to their own, that may seriously question their own, but there is no need to be disrespectful.