Let me try to explain,
The problem basically goes back to questions that arose at Bethel in the late 70’s concerning the accuracy of the Great Crown doctrine. Briefly, in the vision, John “sees” the great crowd standing “in the temple” and “before the throne” (Rev 7:15)
Problem is, this is an identical terminology used to describe beings and things that the Witnesses definitely believe to be in heaven, or to be symbolic of heavenly things. For example, the “seven spirits”, “seven lamps”, the “glassy sea-like crystal”, the “twenty-four elders”, the “four living creatures”, the “golden altar”, and the “144,000” are likewise seen “before the throne.”
The situation is similar with a second phrase used in describing both the great crowd --- ”in his temple” The word John used for temple is naos which literally means “Divine habitation” and was often used in connection the actual temple sanctuary –the Holy and Most Holy. The word is consistently used in Revelation to symbolize heaven.
The Witnesses therefore have somewhat of an interpretive problem given the fact that both the great crowd and 144,000 are “in the temple” and “before the throne”
The most obvious solution was to generalize the two terms. The August 15, 1980 issue of The Watchtower for example argued (rather dishonestly) that the word naos could also be used to describe the entire temple complex including the outer (earthly) courtyards and therefore would not necessarily denote a heavenly location.
The Witness view shifted slightly in 1998 when they discarded Herod’s temple as the model for John’s vision (W98 2/1)
The recent May 1, 2002 issue of The Watchtower further adjusts their view by acknowledging that the word naos is usually more specific than the related word hieron This is done as part of a five point argument that John’s temple vision does not correspond to Herod’s temple with its Court of Gentiles, which is where Witness teaching formerly located the great crowd.
I personally don’t quite understand this argument as it seems to damage their position as much as support it.
Clear as mud?