The problem here, is that the Society is trying to use a little slight
of hand defending a book that has some serious flaws. They are
playing with the start and end date of the Egyptian bondage, by
saying that the Bible is referring to different events in each case,
in order to make the Bible's conflicting scriptures add up.
According to Ex 12:40, the Isrealites were in Egypt for 430 years.
But, if you follow the geneologies in Ex 6:16-20, and Ex 1:1-5, you
find that this cannot possibly be true. Here is the Logic:
Levi came to Egypt with his son Kohath, among others.
Kohath lived to be 133 years old. His son Amram,
who lived to be 137 years old, became father to Moses.
Moses was 80 years old when the events of the Exodus took place.
If we give the Bible the benefit of every doubt, and assume
that Kohath was a newborn baby when he came to Egypt, and
that each man fathered a child on the day of his death, we come
to the following calculation:
Entered Egypt, Kohath is a baby...................Year 0
Amram is born.............................Add 133 = Year 133
Moses is born..............................Add 137 = Year 270
Exodus begins.............................Add 80 = Year 350
Now, if we assume that Amram and Kohath fathered their children
on the day of their death, and the children were born posthumously,
then we can add another two years, giving an absolute maximum
of 352 years in Egypt.
So, even if we accept the unbelievable life span of these men, and
make ridiculous assumptions about their age when reproducing, the
numbers still do not add up.