[abhinai]

I cannot see blind faith mentioned anywhere in these essays. I can also not see it mentioned anywhere that you should not spend any time questioning your idea in the initial stages.

It is likely that you misunderstood PG. He is merely saying that even with all the work, you won't always be right in picking an idea. However, this does not imply that you should put no work on it and start acting on blind faith. In fact I am pretty sure YC does not fund teams who haven't spent at least some time analyzing their idea.