Why should religions and religious leaders be prevented from taking part in any debate affecting society? It's when they try to impose their dogma that it's bad, but not when they give their opinion; after all they are supposed to guide their followers.<quoted text>
As far as I concerned, religions is not "harmless" at all. Religions are always interfering with the states. The Vatican is not harmless at all. The popes are taking parties all the time, so do other religions.
I don't think that Popes have been able to impose anything since the 19th century. But obviously they have some influence in countries where there is a strong catholic presnce.
But I do agree that theist states like Iran of Saudi Arabia are not the way to go, mostly because they don't allow for freedom of expression.
Popes have been unable to stop divorce, contraception, abortion happening in catholic countries, and I think they will not prevent gay marriage either, but they will have their say.