I can denounce whatever crazy beliefs I want to denounce. As Scott Adams (the guy who draws Dilbert) put it:
People keep telling me that I should respect the beliefs of others. That sounds entirely reasonable, at least until you think about it. The problem is in knowing where to draw the line....

But it seems to me dishonest to display respect for all beliefs equally. Surely there are beliefs that deserve slightly less respect than others....

This has to be an even bigger problem for those of you who have a religion of your own. You’re thinking something along the lines of “My prophet talked to a real angel whereas your prophet was evidently taking a drunken forest wiz and thought a tree stump was talking back to him.”....

I also wonder if showing respect for all beliefs is causing more problems than it’s avoiding. The only thing that keeps most people from acting on their absurd beliefs is the fear that other people will treat them like frickin’ retards. Mockery is an important social tool for squelching stupidity.
Some ideas are better than others, and I point out where the bad ideas go wrong, and why they inconvenience people. Afterlife belief is wrong because we have no evidence of an afterlife. And it does cause suffering. Not only when people start depreciating their earthly lives in expectation of an infinite and perfect eternal life, but also when people crash airplanes into buildings because they think they're going somewhere afterwards.