How does one go about proving man is irrational with reason??? If you use reason you must be reasonable...
The problem seems to lie in giving to reason a distorted and inexcusable amount of respect. It is the hierarchy or the forced ordering of the natural drives
that occur within
us that is the important matter. Reason must be something like the ordering and the satisfaction of these inner drives. Upon what basis do you explain your deification of reason? It is all too abstract and wispy, this power that you endow reason with. This is voodoo.
And one does not prove that man is irrational. One only sees, then thinks (whatever thinking
may really be) and then one acts. Enough! Reason is not some light from a hidden god, reason is the workings which originate withing an organic being, a rather nasty and selfish being at that, i.e. man. And so reason itself, considering its origins, is equally filthy farty, disgusting and natural. You are inverting the natural perspective and putting airy and vaporous ideas before man, you are putting the cart before the horse. Because considering all of the claims of different peoples, it was man who came first and his gods came later on. In fact man continued even as his gods kept changing throughout history and region.
Apart from what Nietzsche had to say on the subject, clearly we are both, motivated by desires, achieving our desires by reason... As far as Jesus being human... Well sure, but Jesus is not the problem... We simply have no choice given our information and our ignorance, but to conceive of ourselves spiritually...
I don't believe the business man, for example would share your view. The more we see ourselves spiritually the greater our ignorance. It is not god who conquers nature and makes life tolerable for us, it is the work of science based not upon spiritual considerations but upon hard evidence.
This we do, and this we as humans may always have done... We do as much with rocks, or atoms...It is not the thing we conceive, but the spirit of the thing...
The problem of the nature of reality is important. I don't see god in the rocks I see natural forces that took so long and pressed so hard, I see a giant potentially crushing me like an ant, I see dark blind force.
In the book "Beyond Good and Evil" Nietzsche addresses the exact questions that you raise regarding the real nature of things. It is titled "On the Prejudices of Philosophers".
We have life, soul, or as the Greeks said: animus...Other spiritual conceptions support this life, like justice, or freedom, or rights, and they are like ourselves, moral forms...
I will say this, that it is practically impossible to teach a liberal the truth about morality. But try to think of other places and perhaps even other times than the ones you currently inhabit. How could there be some supra-human force called justice to a five year old girl who lives in the sewer in Brazil, for example (and who will not live to be very old either)?
And once you combine the liberal ideology with material comfort you have certainly prepared a whole people for slavery. For it will be in the name of justice and morality that they (the Americans) give up those same liberties. Aristocratic societies saw things differently. And one could study the ante-bellum American South to find such a different example.
Now; I agree that no heaven awaits us; but that again is not the problem... Heaven is a problem, because it springs from this metaphysical conception of mankind... That is not what I am saying... I am saying we conceive of ourselves and all things spiritually...
Nietzsche never says that there is no afterlife or even that there is no god in the generic sense.
Only some things have being and meaning, and some only have meaning...So if we say reason is a virtue, which no one has ever proved, then the opposite must be true of emotion, that it is a vice... I would say that we can only seldom reason what is good, but know it as emotion, which is to say, Illogically...Here is where I tell you Nietzsche was all wrong...He was still associating animal with bad, and brutal...He could not escape his own morality...He had his time with prostitutes; and do you think he did not judge himself at time, and rebel against that judgement???If we cannot reason out our emotions, and if we canot justify all that we feel; that does not mean they are bad or good...Nietzsche was very good at denying what was humane about people... Where was Mrs. Overman, or little baby overman??? Is love unnatural???Is it rational???His overman was more reasonable than real...As much as he ran down Socrates, he suffered from the same blindness... Both were cut off from natural realtionships, and neither could judge their own society... But morality has nothing to do with knowledge, or mythology... We learn morality before we learn consciously, when we learn to love our mothers... Community is morality... Nature, nation, naive, nascent all come frrom natal, our common mother, our true social unity...No one makes morality, and the reason behind it cannot be systematized and taught...If you get it, you got it before you got anything else, and if you did not get it you will always be an odd duck like N, or like Socrates, or Caesar, or like Napoleon, or like any number of philosophers, or psycho killers, que est'ce que....If it is possible, then on faith we must accept that much of society has its own logic, and not because it was reasoned out before hand, but has simply worked out for the best -sort of logic... Nietzsche never seems more foolish than when trying to judge natural behavior as though it was art, and bad art at that... He had more knowledge than understanding, and not enough knowledge...
Nietzsche's ideas are in his books. Before you rush to judgements about him, I suggest that you pick up one of his books or read one of his essays. He was a highly consistent writer.
You could start at the Nietzsche Channel and begin reading some of the shorter essays in English:
The Nietzsche Channel: Nietzsche's Works: English