People are best judged with conideration of their TIME And PLACE. I do not believe a historical "Abraham" ever existed. I believe he is a fictional character created by the real and anonymous writers of the Bible. However it may be, Abraham is supposed to have been born about 1900 BC according to people who like Usher's (not the musician, the theologian) chronology.
The Bible story tells us that in Abraham's world, child sacrifice was not uncommon. Baal and his crew like baby back bbq.
Abraham was not a modern post-renaissance man, he was a wandering goatherder, with a goatherder's grasp of the world and his place in it.
So I would not say he was crazier than his neighbors who gave their children to "the gods." Death in that sandbox hellhole was paradise compared to the realities of day-to-day survival.
Another view is that just as the story of Cain and Abel showed the dawn of agriculture over a hunter-gatherer lifestyle, so the story of Abraham showed that man moved from sacrificing his children to "the gods" to sacrificing animals. This small change in mindset made it more likely that mankind would persist on earth, otherwise known as Deathworld.
That's my opinion, and I'm sticking to it unless Leolaia or Farkel can convince me otherwise.