OK, mousethief. Never mind the hat. This is more like it. I drop into your local and proclaim to you that the Large Blue isn't extinct in Cornwall after all, contrary to all received wisdom. Now which of the following would you accept as evidence from me?

(a) I saw it written in a book.

(b) I claim I saw one fluttering around in my garden.

(c) I claim I dreamed about them flying over the clifftops at Newquay.

(d) I claim I'd had a vision that it had returned in great numbers.

(e) I tell you that a bloke had told me his granny had seen one.

(f) I show you a dead specimen in a jar.

(g) I claim it had to be back because I'd seen one of its food plants nibbled.

(h) I show you a close-up photo of a Large Blue I'd taken.

(i) I show you a set of dated digital photos clearly showing the butterfly in an appropriate habitat and showing that the habitat in question was located in Cornwall.

If you didn't know me you'd accept (i) only, and then only provisionally. You can fake photos. You'd ask me to take you to the place to see for yourself and confirm my sightings and take your own photos (there's your link with evidence in the scientific sense). I could hardly accuse you of being unreasonable/treading on my beliefs. Once several people have done that you could start to build on the evidence - you look for appropriate food plants and for colonies of the ant that the Large Blue needs for its life-cycle and you might look for the caterpillars in the ants' nests. If you knew me well and trusted me you might just take (b), (f) and (h) as supporting evidence, sufficient even for you to go to take a look for yourself (with little real expectation at best, perhaps) but you would never accept them on their own. If you did, and you went around telling people that the Large Blue was back just on my say-so, you could very well end up looking a fool. We all know about people who build up trust in others then betray them (like teachers building trust in kids in faith schools then teaching God to them as truth).

With religion you can never get past the level of (e). Because of this, religion resorts to reliance on faith. Now that faith, based on (a) to (e), is pretty well all faith and nothing remotely resembling reliable, repeatable, corroboratable evidence. Everyone of religion accepts their God on the basis of nothing more than this, because there is nothing more than this, and they are quite happy to pass this faith on robustly, expressed as spurious certainties, to their children. "Our Father who art in heaven..." is not "Our Father, if he or she (!) actually exists, who may or may not be in heaven, if there is a heaven at all..." Thank goodness atheists don't deal in such certainties, not even Dawkins. The atheist is like you in the pub. You demand a certain level of evidence before you'll even agree to take me seriously. Religion can never reach that minimum level of evidence, because what it comes up with isn't evidence in any real sense at all.

Oh, and I forgot that last resort of the believer. We could call it (j). "Just go outside, look at the sky, the trees, feel the wind and the sun...what more evidence do you need!"