Theism and Belief: Why is the Burden on Us?

An atheist and a theist engage in a friendly debate about the topic of god; specifically, whether or not one exists. The crux of the atheists' argument is essentially that the evidence for the existence of a god is lacking and has not led to the acceptance (on the part of said atheist) of the hypothesis that such a being exists. The theists' bottom line sentiment is that the evidence is sufficient for people all around the world (him or herself included) and it is up to the atheist to accept this evidence/open their heart/be open minded etc (there are many platitudes that are used in this situation).

This discussion has taken place innumerable amounts of times throughout history, and I don't see any reason to believe that it will not continue to do so for at least the foreseeable future. What I find particularly striking about this fact is that the existence of god is one of the few topics for which it is acceptable to claim that the burden of belief/being convinced lies not on the strength of the evidence put forth to bolster the claim but rather on the target(s) of said claims. A few other topics for which this is true are UFO's, bigfoot and the Illuminati/New World Order. Would anyone care to venture a guess as to what it is that these topics have in common? 

There is no proof that any of them exist (none of them do in my not so humble opinion). 

Imagine if someone were to claim that your spouse was cheating on you and the evidence they had to back this assertion was far from convincing and so you express your disbelief. Would it be fair for the person to then state that the evidence is sufficient and you just need to (insert platitude involving hearts or minds)? Or would it be more reasonable for you to tell the person that for such a claim to be accepted the evidence must be congruent with the claim to a degree to which there is little to no room for doubt? In other words, do they carry the burden of proof or is there such a thing as a burden of belief and does that then fall on you? 

In science, philosophy and logic, the burden is one of proof, not belief, and said burden lies on the claimant, not the recipient of the claim. In fact, in the discipline of the philosophy of logic the idea that the burden of proof lies on the one making the claim is held to be axiomatically correct, and for good reason. Imagine how courts of law would function if the defendant needed to disprove their guilt as opposed to the prosecution needing to establish it (beyond a reasonable doubt of course). The doubt can be established by either the failure of the prosecution or the defendant, but the existence of guilt must always be established by the ones putting forth that hypothesis. This goes back to the example of the cheating spouse. Imagine if someone could accuse another of cheating and then sit back and say "prove you aren't or I am leaving?" 

Silly, right? Yet this is what happens with the god claim. The fact that we as atheists do not believe is often said to be a failure on our part as opposed to a failure on the part of those making the god claim to be convincing in their presentation of the evidence. The burden gets shifted away from them and onto us, and this is completely unfair and frankly, a total bastardization of logical thought.  

I don't need to open my mind or listen to my heart (although I have and it sounds fine). If you want me to believe in your god, do a better job in presenting your case. Otherwise, I will continue to believe that you are failing to meet the burden of proof with your rather poor evidence for the existence of an ethereal deity.