In this book the author brings before the reader the importance of understanding what occurred after the Nation of Israel was dismissed by God at the end of the Acts Period: see Acts 28:25-28.
It is his contention that the current dispensation began at that time, i.e. at the end of Acts 28. This was when the Jewish nation was dismissed by God, albeit temporarily, as His chosen people to take His message to all the Earth. This ushered in a new dispensation, which is applicable to us today.
He examines the Scriptures to see what is relevant for us today and what is not … and explains why it is important not to confuse what is written to us with what has been recorded for our learning.