Winky-face noted and appreciated!
But seriously, by my accounting, every standard of evidence I know includes an element of faith. The only differences between them are (a) what is taken on faith and (b) how credulous that faith is.
Namely, I find faith elements in believing:
first/second/third-hand reports, even by trained, neutral observers
expert consensus
single expert opinion
by contradiction
the evidence standards of American civil and criminal trials (note the plural, "standardS". The standards are different between them.)
induction, including (perhaps) mathematical induction
"engineering quality" proof
"mathematician quality" proof
My professional practice as an aircraft mishap investigator is to identify and apply the highest feasible standard from the above list, based on what information is available. "Best practice" in this industry dictates that selection and application of a standard of evidence is a matter of prudential judgement, based on the consequences and probabilities of being wrong, the resources available (evidence, time and $), while being scrupulously open about ones methods.
On historical questions about events of 20 centuries ago, the quality of evidence is not very good. About pretty much everything. What we are left with is Bayesian stuff. Anybody who goes to 0% or 100% draws the raised eyebrow from me. :-)
This is, in practice, a form of equivocation between epsilon uncertainty and sufficient uncertainty to take seriously as an argument.
Step 2 is the tricky one. I suggest reviewing But There's Still A Chance, Right? Humans are, in general, really bad at feeling the difference between epsilon uncertainty and sufficient uncertainty to be worth taking notice of.
To break up the awkward silence at the start of a recent Overcoming Bias meetup, I asked everyone present to tell their rationalist origin story - a key event or fact that played a role in their first beginning to aspire to rationality. This worked surprisingly well (and I would recommend it for future meetups).
I think I've already told enough of my own origin story on Overcoming Bias: how I was digging in my parents' yard as a kid and found a tarnished silver amulet inscribed with Bayes's Theorem, and how I wore it to bed that night and dreamed of a woman in white, holding an ancient leather-bound book called Judgment Under Uncertainty: Heuristics and Biases (eds. D. Kahneman, P. Slovic, and A. Tversky, 1982)... but there's no need to go into that again.
So, seriously... how did you originally go down that road?
Added: For some odd reason, many of the commenters here seem to have had a single experience in common - namely, at some point, encountering Overcoming Bias... But I'm especially interested in what it takes to get the transition started - crossing the first divide. This would be very valuable knowledge if it can be generalized. If that did happen at OB, please try to specify what was the crucial "Aha!" insight (down to the specific post if possible).