OK, so let us stop beating about the bush on the subject of Jesus or Luther and turn instead to "the only begetter" (Shakespeare's words) of all this to do--God. Is it not possible to shut down millennia of wordy discussions with a few basic conclusions?
[1] Asked whether he believes in God, Goethe's Faust hedges by saying, "Call it what you will!... I have no name for it." This is one way of indicating that one cannot discuss God without defining the term. Hence polytheists, monotheists, Deists, Trinitarians--not using the same language--are all talking at cross purposes. What do you mean by "God"?
[2] That there is a God gene or that in our DNA exists an inclination to believe in something higher or spiritual or supernatural is irrefutable. As Voltaire put it, "If God did not exist, we would have to invent Him." But of course that does nothing to prove that a God exists. The wish can be father to the thought; one can practice "wish-fulfillment."
[3] Billions of people have a direct connection, through prayer or mystical experience, with that mysterious entity up in the sky. Tevye the milkman holds periodic personal conversations with Him. And that faith puts meaning into their lives, gets them through the day's allotment of suffering. The New [=loud] Atheists are to be criticized, as Noam Chomsky has indeed done, for trying to deprive people of that elusive happiness and relief. But, it needs to be emphasized, these are subjective experiences that have no claim on reality nor on the credulity of other people. Believers should be encouraged to continue to seek such spiritual nourishment--so long as they do not then tell others how to live; to wit, try to interfere with others' right to follow pornography, prostitution, homosexuality, abortion, assisted suicide, pot smoking, witchcraft, menages a trois, or anything else involving "consenting adults." The latter phrase, which automatically rules out children and coercion, replaces the archaic "God commands."
[4] Proofs of God's existence--or non-existence--are a pipe dream. In this natural (as against supernatural), material world, the only evidence we can come by, the only evidence we can agree on, is scientific. All other kinds of evidence, involving appeals to texts or tradition or authority, are subjective and unscientific. The alleged proofs of God's existence then turn out to be leaky. For instance, once on C-Span, a devout Muslim scientist claimed that he practices Islamic science. He spoke nonsense: If it is scientific, it is not Islamic; if it is Islamic, it is not scientific. Another piece of folly was perpetrated by an Orthodox Jewish physicist in Israel who claims to have scientific proof of the Jewish God's existence. This is more folly: If it is scientific, the entire community of scientists would have no choice but to accept the proof. So far, despite that physicist's book, they have not converted to Judaism. They could, of course, be stubborn or wrong, but do you want to bet the ranch on that proposition?
[5] That brings us to the central predicament. Let us stipulate that one can in fact prove God's existence. Which God does it then turn out to be? The Jewish one? And is it then the Orthodox or Conservative or Reform one? Or the Roman Catholic one, and if so, the one worshipped by the very conservative late William Buckley or Mel Gibson's father, or is it the one worshipped by the radical Father Berrigan and Gary Wills? Or is it one of the many Protestant versions of God? Or is the Muslim God the one that has been proved to exist, but then is it Sunni? Shia? Salafist? Wahabbi? Sufi?
Does or did God speak Hebrew? Aramaic? Demotic Greek? Elizabethan English? Arabic? (By the way, is it not curious that 99% of Christians do not even take the trouble to read their Bible in God's original languages, Hebrew and demotic Greek?) Are we to observe the Sabbath on Friday? Saturday? Sunday? Are we to abstain from swine food or beef? And did God make a covenant with the Israelites, but then change his mind and make one with (Catholic) Christians? Then change his mind again and make a new one with Arabs? And then--you guessed it!--change his mind a third time and make a new one with Protestants? What is going on up there?
The point of this mental exercise is to show that proving the existence of God, were that possible, is actually the easy part. Determining which or whose God is impossible. That brings us to the inescapable conclusion, the one that should shut down all further discussion of God: If God exists, but we have no objective, universally accepted knowledge of his identity, or his personality, or his agenda or how he wants us to please him (because all depends on which book you regard as holy), and if we do not even know in which language he wants to be addressed, then, for all practical purposes, God does not exist. Meaning if he exists but there are no ways of contacting him in prayer or conduct, then it is as if he did not exist. So you persist in believing that God exists? Good for you and long may you flourish in that belief, but so what?
At the risk of practicing what the ancient Greeks called chutzpah (just kidding, you humorless classicists!), the last word has been said on this once important question.