he seemed to have had a big change in attitude though...
We have no idea if God's attitude changed, or even what his actual
attitude was during either time period. All we have to go on are the
supposed words of the mortal men who wrote the Bible.
Actually, what we have are the moods of the mortal men who _selected_
which _existing_ writings would end up in the Bible, which was assembled
hundreds (NT) to thousands (OT) of years after those words were written.
There is a theory that Saul/Paul deliberately designed Christianity as a
"kinder, gentler" form of Judaism that would be more acceptable to the
Romans occupying the Holy Land and thus reduce persecution of Jews, with
the whole Jesus thing being a smoke screen.
how many years separate BC and AD?
Zero, of course. Everything before Jesus was supposedly* born is BC by
definition, and everything after is AD by definition.
(* Nobody knows exactly when that happened, though, and the scholars who
calculated the date of Jesus' birth in 525AD when devising the new
calendar were most likely off by several years. Last I heard, the best
guess was that he was born in September of 7 BC, but it changes
regularly as archaeologists make new finds that contradict the current
dating.)
That should be self-evident from the meaning of the various terms.
S