I strongly disagree. Extraordinary claims require extraordinary evidence. The emergence of life from non-life without any guiding intelligence is an extraordinary claim, and therefore the onus is on the person who thinks it happed to provide extraordinary evidence, not on the skeptic to disprove it.
To be sure, if the skeptic says that “life couldn’t possibly have arisen on the basis of chance and necessity alone,” then the skeptic has set himself up as being able to prove a negative, and must provide a demonstration of his strong claim. But if the skeptic restricts himself to saying, “I’m unconvinced by the evidence so far presented that life could have arisen due to chance and necessity alone,” the skeptic is operating well within the bounds of healthy reason.
I’m a skeptic of the latter sort. I will let Gilbert speak for himself.
Ah, yes, the atheist’s last-ditch stand: postulate an empirically indetectable multiverse to explain away facts about the only universe we can detect that make the atheist uncomfortable.