OK, right from the start I'm an atheist, so this, for me, is 'how do thay account for that?'. But I really am interested.
OK so all three share the same belief that God created the earth and everything / everyone else.
So why did he only reveal himself to a small group of people in what was then, Judeah?
I can understand the point of view that Jews were 'chosen people', so I can understand a god that picks out a certain group. But there were people in Africa, Asia, America, Australia who he just left to their own devices.
And in a similar vein why did God dictate the Koran to only one person? (unless I am wrong here, I appologise if I am).
I realise I am coming to this from an earthly and human point of view, but if I had all that power I'm sure I'd be dictating laws / rules simultaneously on different continents.
I sincerely hope I have not offended anyone, my appologies if I have, it was not my intention.