I've studied parts of the Kabbalah before I became a Christian. There are as many interpretations of it as there are Christian denominations. Some are downright daft. Revelation has several kabalistic details. One I find interesting the Tree of Life since I connect the two witnesses to it.
The "pillar" on the right is associated with Mercy, Love, etc. The one on the is Law, Judgment, Severity. (I find some of the terms used quite confusing myself.)
At the transfiguration I see this: At the top (Crown, Understanding, and Wisdom) is where the voice from the cloud comes from with the Father above (Crown) and the Son below (Beauty) and that goes downwards with Peter below Jesus (Foundation). Moses (Judgement) is receiving the Divine attribute from above on the left (Understanding) and below him is James (Splendor). Elijah (Mercy) is under the Divine attribute on the right, and under him is John (Eternity). (Sorry if this is confusing.) The basic idea is how Divine attributes flow downwards through the three heavens to the earth. Finally the "Kingdom" is established on the earth at the bottom.
Paul also seems to have studied some aspects of what we call kabbalah. When he talks about "mysteries," he is sometimes talking about things some Jews discussed behind closed doors. I also find his use of words interesting here:
Galatians 2:9 And when James, Cephas, and John, who seemed to be pillars, perceived the grace that was given unto me, they gave to me and Barnabas the right hands of fellowship; that we should go unto the heathen, and they unto the circumcision.
Some have read that in an unfriendly way as if Paul meant they "seemed" to be pillars but weren't. I read it to mean they "appeared" like pillars to him. Notice too the unique order he mentions them -- from left to right. It fits because if you were describing them in terms of pillars, you would go, James, Peter and John. Everywhere else, the order used is "Peter, James and John." That is the right order if naming them starting at the bottom and moving up.
So who are the two witnesses in Revelation? I can't say who exactly; but I am confident there is one witness of Justice on the left and one of Mercy on the right. The third witness, so to speak, would Jesus himself not yet in manifestation on the earth.
The two pillars Solomon made were also meant to show the two witnesses with Jachin on the right and Boaz on the left.
There are other pillars too since any saint on the earth in contact with Heaven above can be seen as a pillar.
Switching gears now: Gematria is a kabalistic thing. I repeat that we need to take care since there are so many wildly different opinions expressed; but I've learned some fascinating things. For example, "Jesus" in Greek is 888. Does that help? The numbers 1,3 and 7 are seen as special too; so combinations of those are special. The number 13 is not a bad number, not at all. Many of the sacred names are expressions of 13. YHVH comes to mind -- it adds up to 26. Thus 37 is special too and so is 111 which curiously enough is 3 x 37. This number 111 seems to be the basis for the series of 111, 222, 333 and so on up to 777 and finally 888. The 888 is similar to 111, but up an "octave." Thus the "eighth" day can also be said to be the "first day" of a week. The eight also represents infinity, shown by laying the eight on its side.
Why is 666 "bad" then? It's not meant to be, not any more than "man" made on the sixth day was meant to be bad; but it can be a very dangerous step on the spiritual path. Those who go bad at this point are very bad indeed.
Let me end by saying I won't be offended if this sort of thing doesn't interest you or if you think it might be dangerous. I don't want to push my views on anyone.