Bertrand Russell, refuting the idea that the burden of proof lies somehow upon the sceptic to disprove the unfalsifiable claims of religion:
Many orthodox people speak as though it were the business of sceptics to disprove received dogmas rather than of dogmatists to prove them. This is, of course, a mistake. If I were to suggest that between the Earth and Mars there is a china teapot revolving about the sun in an elliptical orbit, nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes. But if I were to go on to say that, since my assertion cannot be disproved, it is intolerable presumption on the part of human reason to doubt it, I should rightly be thought to be talking nonsense.
Related: Richard Dawkins, scientist, author, and campaigning atheist, quotes Bertrand Russell when answering the question: If you died and arrived at the gates of Heaven, what would you say to God to justify your lifelong atheism?
“Not enough evidence, God, not enough evidence.”