I'll try to take this spot to sum up the reasons for my participation in this thread.
I think the problem is that Valis considers a statement of belief to be the same as a claim of knowledge.
No, I don't consider them exactly equal. This is in part a language problem (there's a difference between belief without basis and belief with basis, for starters), and part philosophical (how can we ever really know anything?). An example:
I believe that a water molecule is made from one oxygen and two hydrogen atoms. Is this a statement of belief or a claim of knowledge? It's the former, for I have to acknowledge that it can be incorrect. Does that matter? No, for all intents and purposes I can treat is as the latter.
Going a step further, there's the question about alien life. "I believe there is alien life" clearly can't be treated equally to the statement of belief in the nature of water molecules. I'll need to add a qualifier, like "probably", to make the higher probabilistic nature of the statement clear. The big distinction is that I can't treat this case as practically true.
Enough with scientists at this point. When a person tells me "I believe that UFOs are alien craft", I can be pretty sure that the person doesn't mean "I assign a probability over 50 % based on this and that to the hypothesis that UFOs are alien craft", he means "UFOs are alien craft". At least, I've never met one. Same goes for many Apollo hoax believers; they don't usually come here to compare evidence, it's to show why their version is true. And, unfortunately, that's the case with many religious believers.
I really don't have much to say about a person who has a religious belief and keeps it to him/herself. I can only show the scientific world-view, which may contain parts that go against specific tenets of the faith, like a young earth. It's up to the person to decide whether he wants to listen or even amend his faith. It's no more telling him what to think than the members here showing evidence based on the official Apollo record to a hoax believer are telling him what to think. While I do not understand willful ignorance, it's not my decision.
What I strongly object in these beliefs is that they seldom are contained within the believer. Indoctrination of children has already been mentioned. So is the inequality based on sexual orientation. Most recent example for me is our deeply religious interior minister demanding tighter limitations to situations where abortion is allowed.
Another objection is that religious faith seems to be out of bounds for criticism. Just recently a suggestion was made in UN to classify such criticism as hate speech. Criticizing a faith is not criticizing the person, and neither is showing that teachings of a religion don't match the observed reality.