The Jerusalem temple no longer exists. It was actually destroyed before John received this prophecy. In the NewCovenant the temple of the Lord is the BodyOfChrist in total and each of us individually, specifically.
So, what does the measurement of the temple really mean? Is it a physical or spiritual measurement? Obviously, since the physical temple no longer exists it must be referring to the spiritual temple.
What constitutes the spiritual temple? To answer this we must think of what constitutes the Spirit. -> the HolySpirit -> My Word is Spirit and it is Life Joh 6:63
Believers are defined by receiving the Gospel and being SpiritFilled. So, from a measurement perspective there are only two dimensions: Word and Spirit.
To be a member of the BodyOfChrist we must be defined by the Word and HolySpirit. This is simply another way of saying we are born of the Word and HolySpirit.