The main reason I'm an atheist

[Alex K]

Could someone tell me roughly what percentage of star light we see in the sky at night emanated originally from stars that no longer exist?

I can't tell you a number, but very big blue stars have short lives, so if you look at a really faint blue star, it's probably far away and hence already gone. The same might be true for red giants. Heck, Beteigeuze might already have blown up, and it's not that far away