Christopher Hitchens had a similar epiphany not long before he died, and even Richard Dawkins said there is no absolute proof of the nonexistence of God, not unlike Cleese’s belief now.
But there was that interview in 2011 where Cleese really unloaded on Christian belief.
Maybe it was the news of that Hungarian gravediggers’ contest last week. Cleese thought, what a wonderful Monty Python sketch that would make, until thoughts of his own mortality intervened. My guess.
IMHO, Fawlty Towers was simply one of the best television shows ever.