From Duane Garrett's recent commentary on Exodus (Kregel 2014):
We should bear in mind that Jericho, as archaeological sites go, is in terrible shape (this is obvious even to the untrained eye when comparing Jericho to sites such as Megiddo, Hazor, or Beersheba). Every archaeological dig to some degree ruins evidence, and this site has been dug repeatedly (and at least sometimes with primitive methods). Furthermore, erosion at the site has been extremely severe (76).
Umberto Cassuto points out that the Sumerian king lists have the names of kings of various Mesopotamian cities together with the number of years of their reigns. Since these kings ruled over separate cities at the same time, their reigns overlapped. But when the list gives the total number of years of the reigns of the kings, it does not give a total for the region as a whole. It acts as though every king had reigned successively, one after another and in a single sequence, disregarding the fact that many kings reigned as contemporaries (92).
In the Bible, the numbers are correct, but they are correct in asserting what they actually meant, and this is not necessarily the same as what we think they meant. If we do not know how the authors computed their numbers or what, to them, as the significance of the numbers, our interpretations will be wrong, even when we read a text that to us seems obvious and unambiguous in its meaning. And in fact, we probably do not understand the reasoning behind some of the biblical numbers (93).
The case against the historicity of the exodus is primarily negative in nature: there is in Egypt no evidence for a Hebrew sojourn or exodus.That is, no Egyptian text refers to either event, and no physical evidence for an Israelite sojourn has been found. Superficially this appears to be devastating, but in reality it is not even surprising.
There are relatively few texts at all from ancient Egypt. Indeed, it is said that an Egyptologist can, in the course of his or her career, read every single surviving text from classical Egypt. The Egyptians wrote on papyrus, an early version of paper, and even in the arid conditions of Egypt almost no papyrus documentation from as early as 1400 BC has survived. It has been estimated that at least 99 percent of all papyrus documents from Egypt have completely perished. Many of the written records that we do have are carved into stone or painted onto tomb walls. Monuments, by their very nature, celebrate the victories and achievements of a government and leave its failures in obscurity. We should also observe that a large number of Egypt's monuments have also been lost. In addition, the Hebrews inhabited mudbrick homes in the soft, wet soil of the Delta. That being the case, it would be remarkable if identifiable and distinctive remains of their presence has survived to be found (96-97).
Whether one supports the Early or the Late Date, both agree on the fact that the city of Raamses is Pi-Riamsese at Tell el-Daba. But the most important fact is that the city there disappeared by the end of the 20th dynasty (c. 1069 BC). If the exodus is a piece of fiction devised much later in Israelite history, how did its creators know that there had been Semites in the area of the long-lost city of PI-Riamsese, or indeed that there had ever been such a city? Some scholars, therefore, will insist that what the Bible calls Raamses was actually the much later city of Tanis. These scholars will claim that the biblical writers were simply confused about the history of the Delta and wrongly placed Israelites at Tanis because that was the only big, Egyptian city that they knew about. But this argument only shows, as Hoffmeier has written, that these scholars "are bent on denying credibility to the biblical narratives at any cost."…By placing the Israelite workers at Raamses (Tell el-Daba) and not at Tanis, the Bible demonstrates firsthand knowledge of Egypt as it was in the latter half of the 2nd millennium BC (98-99).
The sudden appearance of Israelite settlements at the beginning of the Iron Age–with no convincing explanation except that they came from outside–also supports the idea that there was an exodus and conquest (99).
The structure of the Tend of Meeting, as described in Exod 24-40, is regarded by many scholars as a piece of fiction, a literary creation of the Priestly writer (P) during the postexilic era…Kitchen has demonstrated that this thinking arises from total ignorance of the actual practices of ancient Near Eastern peoples…It is doubtful that a postexilic writer would be able to describe accurately a 2nd millennium-type portable shrine (98-99).
If this causes us to despair, we do well to remember that Exodus never alludes to the Hyksos, or to Ahmose, Hatshpsut, Thutmose III, Amenhotep II, Akhenaten, Ramesses II, Merenptah, Ramesses III, or to any other pharaoh that might be associated with the oppression or the exodus. If we find ourselves vexed at trying to defend, for example, that Thutmose III was the pharaoh of the exodus, we are becoming distraught over defending a claim that the Bible never makes. Not only that, but we cannot be sure that details regarding the chronology of the Egyptian pharaohs or of Canaanite archaelogy may not be revised as research continues (101).
A large number of surviving texts from ancient Egypt are monumental; almost all of the papyrus documents have disappeared. By contrast, the clay tablets popular for documentation in Mesopotamia could last for millennia (27).
We, too, have limited knowledge of Egyptian history (lists of pharonic names and the remains of tombs and temples built by these kings does not constitute a history). Indeed, in contrast to what we know of classical Greek and Roman history, Egyptian historiography for the New Kingdom is staggering for its meagerness, for its fragmentary nature, and for how much of it is really scholarly speculation (no disrespect for the intelligence, diligence, and careful scholarship of Egyptologists is implied or intended). The fragments of Manetho for Egyptian history can hardly be compared to Thucydides for Greek history or Polybius for Roman history, and these two are but a small piece of the iceberg of information available on the classical world.
We should learn as much as we can about Egypt so that we may speak from light and not from darkness, but we should teach the biblical history and not some reconstructed, hypothetical model that tries to make definite what the Bible leaves indefinite (103).