Abraham

But if the voices in your head Say to sacrifice your kid To satiate your loving God's Fetish for dead baby blood It's simple faith, the Book demands So raise that knife up in your hand! Abraham (אַבְרָהָם (Avraham) in Hebrew, and ابراهيم (Ibrahim) in Arabic) was a psychologically disturbed (probably  schizophrenic) hero of his time who is most notable for being a central figure in the religions of Judaism, Christianity, and Islam and for hearing God's arbitrary demand to kill his son and then actually trying it. Despite the fact that his actions are now crimes today and considered reprehensible even by the religious, people of the Abrahamic religions still worship Abraham as the ultimate virtuous God believer. There are no sources on Abraham apart from an ancient and unverifiable book and copycat texts that followed. The consequences of this story has doomed the earth for several thousand years and still does in the 21st century. A pseudepigraphical work named 'Testament of Abraham' narrated God's attempts through archangel Michael to take Abraham's life.

His sons, and subsequent bloodlust involving said sons
He had a son, Ishmael, with his Egyptian slave Hagar. Then God told Abraham to father a son by his own wife, Sarah, and Isaac was born.

Then God told Abraham to get rid of his slave and her son Ishmael. Islamic sources cast Hagar and her son Ishmael as favoured by Allah and the ancestors of all Arabs.

According to the story in the Qur'an, Hagar and Ishmael were wandering in the desert, almost dying of thirst, until they found a well in Mecca. Later, Ishmael and Abraham built the Kaaba in Mecca.

According to the Abrahamic religions, Abraham was commanded by God to sacrifice his son held by Christians and Jews to be Isaac, whereas Muslims believe that Ishmael was to be sacrificed). Abraham accepts the command and prepares to slaughter his own child, but at the moment of the actual killing, he is stopped by an angel who chucks him a ram to be sacrificed instead. If Abraham lived today he would be incarcerated for trying to murder his child and would probably be given psychological treatment. One common misconception about this event is that Issac was a young child at the time. This is contradicted by the fact he actually carried the wood for the sacrifice himself, implying he was at least a teenager and either fine with the idea or ignorant of the fact that he was the proposed sacrifice.

As if this biblical story wasn't disturbing enough, the modern philosopher Soren Kierkegaard uses Abraham as an example of a Knight of Faith. He praises Abraham's willingness to carry out God's command and his unshakeable belief that things would work out as they should.

Child sacrifice
As noted in the article about Isaac, it has been suggested that there may be an older version of the story in which Abraham actually kills his son according to biblical scholar Tzemah Yoreh. This is hinted at by Genesis 22:19, which describes Abraham but not Isaac as returning from the mountain with that earlier version having been changed once human sacrifice was frowned upon in Judaism.

Historicity
For much of the 20th century, the scholarly consensus reflected the arguments of figures such as William F. Albright that Abraham was a real person, living some time in the second millennium BCE; this chronology was based on knowledge of customs, proper names and other details of that time. However, this was challenged by a later wave of scholarship: in 1975 came two works by north American biblical scholars, The Historicity of the Patriarchal Narratives: The Quest for the Historical Abraham by Thomas L. Thompson, and John Van Seters' Abraham in History and Tradition, who both concluded that there was no actual evidence for the existence of Abraham, Isaac, and Jacob. In particular, Thompson concluded that many of the facets of the Abrahamic narrative were reflective of the Iron Age, leading Thompson to conclude that the Abrahamic narrative was concocted up sometime between the fifth and second centuries BCE.

There have been attempts to match the Biblical narrative to real places, with Abraham's supposed birthplace of identified with various historical sites, most notably  excavations at Nasiriyah, and his later residence at Haran is usually matched to  in modern-day Turkey.

Even among those who believe in the historical existence, the dominant theory of Biblical authorship holds that the stories of Abraham and the patriarchs in the Book of Genesis were probably written around the Babylonian exile of 6th century BCE. This means that there must have been many hundred years of transmission of oral tradition before it was put into writing. Almost any oral tradition could be transformed over 500-1000 years, and could have been coloured by later traditions or modified to fit in with past or present names and customs. Short of a time machine, it's unlikely there will ever be real evidence that Abraham existed or any factual information about him.

The scarcity of references
Another significant problem is that there is very little reference to the Patriarchs (including Abraham) in the pronouncements of 'later' great prophets like Jeremiah, Hosea or Isaiah, whose prophetic words date from the eighth and seventh centuries BCE. "It is as if these supposedly basic stories of Israel's origins a thousand years before were largely missing from the consciousness of Jeremiah, Hosea and Isaiah, whereas references to the Patriarchs appear abundantly in material which is of sixth-century or later date".

Genesis also makes some curious references to peoples like Philistines, who come from a later period of history. Similar references are made to the Arameans who were supposedly descended from Aram, Noah's grandson and whose settlement in areas reasonably close to Canaan/Palestine couldn't have begun earlier than 1200 BCE, almost a thousand years after Abraham was believed to be born.