"Eight is the number of new beginnings. Every time there is new light, a fresh moving of God, a mighty reformation, a great and glorious revival in the midst of the Lord’s people who dwell in Babylon — there is a separation, a coming out, and a new thing is birthed. We see it in the Waldenses, the Huguenots, and various other groups throughout church history. We see it in the Reformation when the Protestant churches came out of the Roman Catholic Church with the great truth that the just shall live by faith. The Anabaptists, the Quakers, the Methodists, the Plymouth Brethren, the Puritans, the Pentecostals, and many, many other groups came forth out of the historic Protestant church systems as they received new truth and sought to follow the Lord into new realms in the spirit. Each of these is represented by the “eighth” — a new beginning. And yet, as church history unerringly confirms, every new move of God has subsequently gone into apostasy!"

"It is a great and terrible mystery — the eighth is OF THE SEVEN. There is the key to the mystery! It does not mean that the eighth is “one of the seven.” Oh, no! The preposition “of” is from the Greek “ek” meaning “out of,” and must be understood, as so frequently in John’s writings, to denote origin and identity of nature; this eighth beast is not different in nature from the seven, but is the concentrated essence of them, and therefore destined to not maintain its cuddly innocence and childlike purity, but to go into apostasy — into perdition. It should be very evident to us all that this “eighth” beast, this new beginning, when a people are drawn out of a religious system into a new walk in the spirit, in most cases contains right within it the seed of the Babylonish system out from which they came. Thus they are the eighth — but the new thing is of the seven — same old business under a new regime — and the latter is of the same spirit as the former! Now tell me that isn’t a mystery! The new move has the same potentiality and proclivity for carnality and sectarianism built right in from the very beginning because both the nature of the harlot and the nature of the beast lurk within the heart of every man. So through the generations, rising up in many expressions, the harlot and her beast are within us! And that, my beloved, is the mystery! The various religious kingdoms of man have brought to the full (seven heads, seven mountains, ten horns) the workings of Mystery Babylon the Great!"

Much more in the link:

https://www.godfire.net/eby/rev197.html