Why does "1984" contain long passages from "the book"?

I assume you
mean why does the movie version include long passages read by the narrator from the book
itself.  The reason for this is why I believe most movies can never match the book in intensity
and meaning.  When reading the book, we get into the heads of the characters. We know their
thoughts, innermost feelings, fears, hopes, dreams, failures.  It is very difficult to portray
this accurately when portraying the characters in the movie without doing just what the director
of the movie did--he gave us long passages of thoughts, feelings,
motives, fears, etc. from the characters while also feeding us images and graphics which would
help us grasp the overall message.  It is nearly impossible to accurately depict characters in a
deeper book (like 1984, Lord of the
Rings, or even Harry Potter) in a movie that only
lasts 2 hours.  So much of the character's beliefs, opinions, feelings, thoughts, etc. is left
out of the movie because of this difficulty.  I was pleased to see that
1984's director decided to include passages from the book in an
attempt to do the book justice.