Israeli archeologists have more reason than anyone to prove Exodus, yet cant find evidence of settlement that could have accomodated up to 3 million....from that size population one could field a decent size army as a serious challenge to oppressors.
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The mystery ghost writers of the gospels have Matthew putting the birth of Jesus in the time of Herod I (the great) while Luke puts it almost a decade later in 6 AD, when Rome canned the client King arrangement by booting out Herod Archelaus (son of Herod I) and ruling Judea directly through the Roman legate of Syria Publius Quirinius - who conducted the census that had Joe and Mary in Bethlehem.
Based on the carrying capacity of the cultivatable land available to the Egypt at the time, it's estimated they had a maximum total population 2.9 Million people. Less them the 3 million people you suggested above. In other words, this would of been a total Exodus of all people in Egypt from the fertile Nile Valley to the desolate desert of the Sinai peninsula, which in the best of times, does not have the carrying capacity to support 3 million people with the farming technology of 1250 BCE.
You didn't use logic or reason to get into this opinion, I cannot use logic or reason to get you out of it.
You cannot over estimate the unimportance of nearly everything. John Maxwell