There have been a few threads on the missing chapters in the new book, Worship the Only True God compared with the old United in Worship book (first published 1983). With the missing chapters you can draw your own conclusions as to why they have been omitted at least there isnt any ambiguity.
Other chapters of the book are almost identical to the old, with some bits being omitted, other being re-worded and others being copied word for word. So heres where the problems comes in.
In the old book, the chapter Keep Close in Mind Jehovahs Day started off with a discussion of the 1914 generation, quote; The Scriptures clearly show that the generation that saw the beginning of Christs presence would also see the great day of Jehovah in which he executes judgement against all who practice unrighteousness. That generation is now well along in years.
Reference to this generation is of course totally omitted from the new book, which replaces the old thoughts with, quote; The nearness of all that is emphasized by evidence that Christs invisible presence began in 1914 and since then we have been in the last days of this wicked world. No proof is offered in the book of why the statement can be made about Christ ruling from 1914 onwards.
This chapter gets worse though. In the old book subheading Separating of People first dealt with the parable of the wheat and the weeds and then with the separating of the sheep and the goats. The next subheading, What Lies Ahead? states Are there prophecies still to be fulfilled before the great and fear inspiring day of Jehovah begins? Yes! The separating of people over the Kingdom issue is not yet finished.
The new book mentions the wheat and the weeds but not the sheep and the goats. It talks about the other sheep but nothing about the separating of the sheep and the goats. However, the subheading What Lies Ahead? is almost identical. The same section in new book reads almost identical to the old; But are there prophecies yet to be fulfilled before that fear inspiring day begins? Yes. (note: exclamation mark omitted in new book) For one thing, the separating of people over the Kingdom issue is not yet finished.
Spot the problem. In the old book the separating of people was a reference to the previous section talking about the sheep and the goats. However, since 1983, the thought about when the separating of the sheep and goats takes place has changed.
The Watchtower 1995 10/15 indicated that the separating is yet in the future; quote
What Does It Mean for Us?
21 What, though, does this fresh understanding of the parable of the sheep and the goats mean to us? Well, people are already taking sides. Some are on 'the broad road leading off into destruction,' while others try to stay on 'the cramped road leading off into life.' (Matthew 7:13, 14) But the time when Jesus will pronounce final judgment on the sheep and the goats depicted in the parable is yet ahead.
In other words, the new light of 1995 says the final separating of the sheep and goats is yet future. But the new book still refers to a separating work that is going on now!
So to cut a long story short, the new book is a re-hash of the old, but unfortunately, whoever did the re-hashing didnt even bother to take the time to examine the context of the text they were re-hashing.