answer:One would assume that doubt (which drives verification) is the antithesis of trust. I suspect that the original writer wasn’t thinking of trust so much as a more general openness to the idea. Give the benefit of the doubt, but then see to the doubt. Might also be an exhortation to fake trust while you verify. Wikipedia states that it’s a Russian proverb. In a similar vein, the Russians give us, “Trust in God, but lock your car.” I’ve long heard about how deeply cynical Russian culture is, but this list of proverbs really drives it home.