[SnakeDoctor]

Atheism is a philosophy which rests on a contradiction — that all assertions require proof, except the assertion that there is no God. “If I can’t see it, it doesn’t exist” is the philosophical equivalent of putting your fingers in your ears and shouting “lalalalala”.

SnakeDoc

[stormer]

You cannot prove a negative.

[left that other site]

“If I can’t see it, it doesn’t exist”

Precisely!
We know Gravity exists because we see its effects.
We know quarks and nuetrinos exist because of the effect they have on other subatomic particles.
We know there are planets orbiting around certain stars because of the perturbations in the star's activity.

The Psalmist said:

The heavens declare the Glory of God,
And the Earth, his Handiwork.

That's pretty reasonable, in my humble opinion.