Why do you say that the ABOVE is false, but the BELOW is true?
You have faith that the god of the bible does exist, for you cannot prove that he does .
Supersimple! Proving a negative is a logical fallacy. One need not prove a negative. One attempts to prove a positive.
1.) If you believe God exists, then you have faith (VALID)
2.) If you don't believe God exists, then you don't have faith (ILLOGICAL)
3.) If you have faith, then you believe God exists (ILLOGICAL)
4.) If you don't have faith, then you don't believe God exists (VALID)
There are four ways to construct the assertion. Two are valid constructions, two are not. These are basic constructs of first-order logic. By the same token, and perhaps more relevantly:
1.) If God exists, then there must be evidence of his existence (VALID)
2.) If God doesn't exist, then there must not be evidence of his existence (ILLOGICAL)
3.) If there is evidence of God's existence, then God must exist (ILLOGICAL)
4.) If there is not evidence of God's existence, then God does not exist (VALID)
The designation of logical and illogical reasoning is not arbitrary; it is trivial to show why the illogical assertions are in fact illogical. Most atheists/agnostics rightly use the #4 assertion as the reason for their particular reasoning. The only way to invalidate that reasoning is to invoke #1 by providing the evidence to support the premise. Unfortunately, many people of all religious stripes use constructs like #2 and #3 to support their belief, which an educated person will immediately recognize as illogical arguments. The old saying "you can't prove a negative" is actually a reference to illogical construct #2. All these forms actually have proper names in math, but I won't bore you with them.
I hope this helps explain why people say that some statements are true while very similar statements are illogical. It isn't arbitrary posturing, but actually based on mathematical principles of correct logical form. All the people arguing on this forum will get WAY more mileage if they stick to using the logical forms for the arguments; people who consistently use illogical arguments will be rightly ignored by those who recognize them as such.