A common bone of contention between non-believers and believers is the subject of "truth".
I understand truth as a declaration about the world that matches the way the world is.
Deacon Duncan at Freethought Blogs - Alethian Worldview and Evangelical Realism is having just this discussion with a commenter.
I won't repeat Deacon's words here, but I agree with him. If it can't be detected in the world, it doesn't qualify as "truth". This disqualifies claims that cannot be detected in any way - the invisible, the immaterial, the supernatural, the imaginary - a personal god, for instance.
It can be said - over, and over, and over again - that allowing claims for which the claimant is unwilling or unable to provide the slightest indication of its existence, opens the floodgates for all claims that lack evidence. The claim that I have a herd of wild elephants in my spare shower stall must then be met with the same seriousness and respect as the claims of a personal god, if claims of a personal god are allowed to be entered into public discourse. This doesn't disallow discussion of a personal god or a herd of shower-stall-based wild elephants when held among like-minded individuals - in private, you can discuss any whacky proposition you wish. Just don't let this whackiness pollute the world outside your home.