The two have nothing to do with each other. In the first case, we're dealing with something that is a scientific fact of which most people happen to be unaware. A public awareness campaign would almost certainly change the majority belief, if only they were told they are harming their children. No one has a conviction about fires, even if they really like them. The latter case is about faith, which is not a matter of rationality. Religious people have faith as a spiritual matter, and faith doesn't have regard for science. And specifically in the case of religious fundamentalists, they see their perverted version of faith intentionally as anti-science, resisting the devil trying to sway to eat the fruit. Its not as if they just don't know yet what the science says about such matters, they are above it. There are lots of harmful things that each of us engages in. When it regards something that we are really familiar with, and have never considered to be harmful, of course its going to take some denial to get past. I think that's natural, but its not the same as active, purposeful denial, IMO.
The important thing is that I will harbor no illusions that my actions hold no negative consequences.