"How much evidence does it take to believe or to know?"
I don't think we ever assert 'belief' or 'knowledge' in the abstract, so there is something of a straw man in the question. We are all aware that there is no ultimate proof available for anything.
Instead, such terms are understood according to the context. If I 'know that Jesus loves me', everyone gets that this means something different to my knowing the boiling point of water or believing that the earth orbits the sun, or that the prisoner is guilty as charged. Similarly, the degree of certainty that goes with any claim of 'knowing' something is also understood according to context. If it isn't - for example if I claim I know Jesus loves me because he wrote me a letter, or that I have verified the boiling point of water through instinct, then this would provoke a discussion because this isn't the usual context for such claims.
So it's not 'How much evidence?', rather it is 'What sort of evidence?', the answer being 'That varies depending on the subject'.