Burden of Proof: Using Known Concepts to Reveal Eternal Truths

Where is the proof? Why believe in something if there is no evidence? Also, why believe in something when there is evidence that runs contrary to a particular belief? This is basic logic and a reason why most deny a deity. Most who deny a deity argue there is no evidence. Also they point to scientific evidence to validate their skepticism. However, what if there is evidence and evidence that is overwhelming? Those who deny a deity have every right to demand evidence. Yet, what will they do when they are provided proof?