@Justanatheist and
@Jayhawker Soule, as promised, some evidence of the authenticity of Abraham. Unfortunately, I don't have all of my sources with me, but I'll do my best.
Archeologist
Dr. Yitzchak Meitlis, who studied under the famous
Prof. Israel Finkelstein, wrote two books on the subject of the bible and archeology. In his book "Excavating the Bible", he dedicated a chapter to the Patriarchal era. I'll summarize some of his main points and include info from other sources as well:
Camels:
Though a point still touted by some as a way of disproving the authenticity of the descriptions of Abraham's life, the notion that camels were only domesticated much later than his life was already disproven decades ago. For example, a 17th century document from
Alalakh mentions stocking up on feed for a camel (see
here).
Ofer Bar-Yosef wrote in "Studies in the Archeology of Nomads in the Negev and in Sinai" that there's evidence that camels were already domesticated in the 4th millennia BCE, and camel bones were found together with goat bones in Be'er Resisisim, dated to the 3rd millennia BCE.
Personally, I'm a little confused at Ben Yosef and Sapir's conclusion (in the
link @Jayhawker Soule
brought) based on the finding of a camel skeleton in a 10th-century site. Meitlis seems to be equally confused about conclusions such as this; he wrote in a footnote in his book that certain proponents (
Prof. Nadav Na'aman, Finkelstein, etc) of the later-domestication-theory continue to push the view, ignoring evidence for earlier domestication. He is unsure why they continue to do so. Ben Yosef and Sapir are both from Tel Aviv University, which is where Finkelstein and Na'aman are from, so there's quite likely a connection here.
Names of cities and towns:
The cities and towns Abraham wanders around - such as Beit El and Hebron - are sites known to have been settled at the time, while other sites that were settled only in later periods - and became central in the region even later - are not mentioned. If the text had been written by someone from the Iron Age I period and onwards, would it not make sense to include sites important to those subsequent eras? Dr. Meitlis in his second book, "Parashat Derakhim: Archeology and Geography in the Weekly Torah Reading", pg. 32-33, points out that Shechem is also mentioned, but not as a town: "Abram passed through the land as far as
the site of Shechem" (
Gen 12:6) - which shows that Shechem still wasn't settled at the time. Indeed, in the Execration Texts of the early 19th century BCE, several important Canaanite cities are mentioned, but not Shechem. Shechem is mentioned later on during an Egyptian conquest, decades later, in the middle of the 19th century, but even then, not yet as a city but as an area/land/territory. In the biblical story of Jacob, he meets the ruler of Shechem, Chamor, and his son, also called Shechem. Perhaps there's a hint here that Shechem was named after the person who first settled the Shechem area, i.e., it was first "the land/territory of Shechem" before becoming an actual city.
Abraham's lifestyle:
Abraham's lifestyle reflects that of the typical Middle-Eastern/Mesopotamian nomad during the Middle Bronze Age: Searching for water sources, travelling around the Be'er Sheva-Hebron area in search of pasture, etc. See
here and
here. It is also known that shepherds travelled down to greener areas in Egypt, which eventually led to the rise of the Hyksos dynasty, originally Asiatic shepherds themselves. Abraham had ties to the Arameans - though it was rightly noted by Na'aman that we only have evidence for the Aramean Empire from the 12th century BCE and onwards, the name "Aram" already appears in a few documents from the third millennia BCE, which ties in to the descriptions of the Arameans in the time of the Patriarchs (that they are not described as a kingdom but rather as shepherding clans) (and see Prof. Yoel Elitzur's study on the possible location of Kir, the first home of the Arameans
here).
Geography:
Prof. Yoel Elitzur and
Prof. Amos Frumkin conducted a research project some years ago, examining the rise and fall of the water levels of the Dead Sea (see
here, and Hebrew
here). It was discovered that during the time of the Patriarchs (20th-19th centuries BCE), the water level was so low that there were portions of the sea that were completely dry, whilst in later times, such as the time of the Exodus, this area was once again filled with water. Why is this significant? Because it says: "all the latter joined forces at
the Valley of Siddim, now the Dead Sea" (
Gen. 14:3) - in the time of Abraham there was a valley in that area, but later on - it was part of the Dead Sea.
The Philistines:
I'll note first that I heard from
Prof. Aren Maeir, who has headed the digs in biblical Gath for the last 25 years, that the five main Philistine cities weren't built by the Philistines but by earlier Canaanites, so dating the Philistines doesn't date their cities, which is why earlier mentions of Philistine cities (such as Gaza in
Gen. 10:19) aren't problematic. Furthermore, I heard from
Dr. Amit Dagan that the only reason the people who settled in the Philistine cities are called by archeologists today "Philistines" is because that's what the bible called them. Similar though not identical terms were found around Egypt and Anatolia, apparently referring to groups of people that came from the Mediterranean area - however, there are very few Philistine texts, and out of those deciphered, none feature the Philistines ever referring to themselves as such. In fact, it is unknown how they referred to themselves. Therefore, if the bible chooses to refer to a number of groups of "Philistines" - it seems there isn't currently any evidence to the contrary.
With that said, as Dr. Meitlis pointed out, there is in fact evidence for two different Aegean groups having settled in Canaan: The first group are the Philistines that were probably those referred to along with the rest of the "
sea peoples" in Egyptian texts, and eventually settled in what became the Philistine area of the Israeli coast. The second group settled in the Negev, as described by the bible (see for example
Gen. 26:1 and
Gen. 20:1) and as is evident from Minoan-style findings in the area, such as burial in clay larnaxes (see
here) and texts written in the Minoan alphabet.
There's much more evidence, which is why I recommend checking out Meitlis's book. I hope I did the matter a little justice.