Don't believe in God? Why not?

[sdtPikachu]

"I can see that this conversation will go in somewhat the way of the last one."

Yep... sadly enough. Most people can't have an oen discussion on these views without taking it too personally.
Of course it's not made any easier by remarks I find insulting which are responded with "How is it insulting?" instead of "I'm sorry, I just find it difficult to see things from your perspective"

"Scientist have yet to discover one thing on earth before humans came."

?!?!?!?!?
Have you even HEARD of geology? Palaeobiology?
We have discovered literally thousands of species which do not and never did co-exist with humans.

"BUt how can they discover who created earth?"

Maybe you should say "what" created the earth. You have no evidence it was god, I have no evidence it wasn't sneezed out of the mouth of a creature called the great green arkleseizure. Which one of us is right? It's opinion versus opinion. Where the difference comes in however is that science gathers more and more information daily, which lead to new avenues of thought, new hypotheses, new theories. Religion does not do this.

What happens if conclusive scientific proof that the universe WAS sneezed out of the mouth of a creature called the great green arkleseizure was found out tomorrow? Would you accept it?

"There may be clues, but it's impossible to make a fact out of these clues unless you go back in time and whitness it for yourself."

You misunderstand the nature of science. We look at things as they are today, and we formulate laws... such as "if you drop an apple, it falls". Now it seems likely to me that this has been the case throughout time itself. In fact, we can even see gravity forming star systems at this very second. No, we can't see exactly what happened a billion years ago. That is why we gather evidence, formuate hypotheses and eventually theories. We see what we can see from what remains of the time... we think "how can this have happened?" and we create a hypothesis based on this. We then test this by looking at other examples of things that happened at the same time and/or at a different place, and see if that fits our current hypothesis. If not, we wonder why this is. If we can think of an alternative hypothesis that fits the evidence better, that will become our new hypothesis, until we have gathered more evidence which does not fit our current hypothesis. Thus we continually remodify our thoughts on the matter to fit in with observation.

See "scientific method"

"I don't that a Scientist is crazy enough to create a time machine either."

So you say because we can't create a time machine, we can't say that this fossil is 120 million years old? Explain your logic please.