How can the Bible or Koran be the basis of a peaceful and humane religoin?

How can anyone point to the Koran or the Bible and say these documents are the bedrock of a peaceful and humane religion?  (This may apply equally to other holy scriptures but I am less familiar with them, so let's stick to these two).  They are full of blood-curdling violence and attitudes that would be completely unacceptable if they were espoused today.   But their violence and anachronistic attitudes are not at all surprising; they were written by people who were ignorant about the world around them, when science as we know it today did not exist, when human life was cheap and hung by a thread, threatened by hunger, natural disaster and disease, where people attacked and murdered each other over food and water as well as the gods they worshipped.

So when St Paul espouses slavery, or The Prophet wields a bloody sword, or women are treated as chattels, we should not get too hung up about it.  That was then, and this is now.  What the authors of these sacred texts thought 1300 or 2000 years ago is irrelevant to our lives today.  Sure, they have contributed to the intellectual development of the human race, and are interesting from an historical perspective, but as a species we moved on.  We learned to order our lives better and to control our environment so that life became safer and in doing so we had time and space to become more tolerant of each other, to show empathy for other human beings, and we replaced ignorance and superstition with science.

The Bible and the Koran are interesting historical tracts, but to rely on these documents to inform your behaviour is to say that you believe the world in which they were created is a better place than the one you live in today.   Some people may think so; the real fundamentalists, though I don't see them rushing to live without clean running water, modern medicine, almost universal literacy, modern communications (including you tube and Facebook!) and with fear that their lives might be extinguished tomorrow by a wild animal, a microbe or the tribe down the valley.  

Let me say, however, that I don't think it is necessary to live without belief completely.  You can believe in the inherent good nature of (most) human beings; that most of us know what ethical behaviour is and display it without recourse to "the good book".  We can believe that an enquiring mind is always better than a closed one. There will always be dangerous thoughts out there , but approach other ideas with an enquiring and scientific mind and the ascent of mankind will continue unabated, albeit with some hiccups on the way, even further from the distant and irrelevant world which spawned the holy-to-some Bible and Koran.