It only seems that way because there are a few hubbers who are, well lets just say, 'enthusiastic' about their beliefs and tend to pop up everywhere.
I don't do the forums as much either - as 'little two two' has already mentioned - really because it can be quite hard to ask a question at times without getting a sermon from an 'enthusiast'.
Having said that, the vast majority of hubbers who do have beliefs of one kind or another, are very normal, lovely, interesting people and are sane about their personal beliefs. It's only a very small minority who just about give themselves nervous breakdowns trying to get 'the message' across to all us non- believers/heathens at every possible opportunity.
But that's the way Hub Pages is, a free page to write on, and I wouldn't have it any other way. There are loads of other topics on the site that are fascinating and very informative. It's just a case of skipping over what you don't like.