Assuming "religious" means "not thought out or reasoned out", or valuing someone's opinion lower because of their religion, is either a severe prejudice, or downright discrimination based on religion. One goes against what you stand for, the other as well and is technically illegal to boot. Congratulations!
(As an aside, people dismissing posts of yours because they're yours, while it annoys me greatly, is not exactly the same - assuming A will rob me because M and Y have robbed me in the past is racist, assuming A will rob me because A robbed me in the past can be sensible. It's not discrimination if it's no extrapolation from a minority to a group. It's still a prejudice, though, and if it's applied to "all those leftist hippies", it's just as bad. if it's "jsut against Charlie", it's technically not discrimination)
Remember: being intolerant against the intolerant is still intolerance. Being intolerant towards a group because of an extrapolated idea based on personal experience with members of that group is intolerance. Claiming stienman isn't smart or doesn't think is plain wilfull ignorance on your end (which is something entirely different from agreeing with him - I disagree with him on most ethical or religion-affected subjects)