If you don't understand the difference between asserting the existence of an all powerful invisible being with specific powers and requirements set on humanity and believing in such and merely not asserting anything in particular about things we can't see or measure then you are the one who needs to study logic futher. Just because you say "Atheism is an act of faith" does not make it so. Of course most of the great religious philosophers have spent a great deal of time explaining "Why they believe". For instance C.S. Lewis, Thomas Acquinas. Many, perhaps the majority of non-believing philosophers have simply noted that and moved on to write and think about other areas, like truth, beauty, power, language and economics.
Okay, look at Jillete's explaination. He said atheists start with nothing, and search for proof God exists, and when they can't find it, conclude He does not exist. Fine, but one cannot prove God exists. Religion is by its nature, an act of faith. So Jillete's explaination of the atheist's argument is false. This is the same thing I say.
So my argument to the atheist, if proof is required to prove the creation of the universe by supernatural means, then proof is required to prove the creation (not existence, creation) of the universe by natural means. Nobody can prove either. That is the mystery of man's existence.
Note Jillete says "I believe that there is no God." Not "I know there is not God."
Then he says "But, this "This I Believe" thing seems to demand something more personal, some leap of faith ...
Jillete is one of the few intellectually honest non-believers. Maybe that is why he chooses not to call his non-belief atheism.
You mention C.S. Lewis. Remember, his realization that Jesus was real was a result of trying to prove Jesus was not real.