Albert Barnes Commentary Revelation 17:8

"The beast that thou sawest was, and is not; and is about to come up out of the abyss, and to go into perdition. And they that dwell on the earth shall wonder, [they] whose name hath not been written in the book of life from the foundation of the world, when they behold the beast, how that he was, and is not, and shall come." — Revelation 17:8 (ASV)

The beast that thou sawest was, and is not. At the end of the verse it is added, and yet is—the beast that was, and is not, and yet is.

Three things are affirmed here:

1. First, there is a sense in which it could be said of the power referred to here that it “was,” or that before this it had an existence.
2. Second, there was a sense in which it could be said that it “is not”—that is, that it had become practically extinct.
3. Third, there is a sense in which that power would be so revived that it could be said that it “still is.”

The “beast” referred to here is the same one mentioned in Revelation 17:3 and Revelation 13:1, 3, 11-16.

That is, there was one great formidable power, having essentially the same origin, though manifested under somewhat different modifications, to one and all of which might, in their different manifestations, be given the same name, “the beast.”

And shall ascend out of the bottomless pit. ek tēs abussou. On the meaning of the word used here, see the notes on Revelation 9:1.

The meaning here is that this power would seem to come up from the nether world. It would appear at one time to be extinct, but would revive again as if coming from the world over which Satan presides, and would in its revived character be such as might be expected from such an origin.

And go into perdition. That is, its end will be destruction. It will not be permanent, but will be overthrown and destroyed. The word perdition here is properly rendered by Professor Stuart destruction, but nothing is indicated by the word of the nature of the destruction that would come upon it.

And they that dwell on the earth. The inhabitants of the earth generally; that is, the matter referred to will be so remarkable as to attract general attention.

Shall wonder. It will be so contrary to the regular course of events, so difficult of explanation, and so remarkable in itself, as to excite attention and surprise.

Whose names were not written in the book of life from the foundation of the world. See the notes on Revelation 13:8.

The idea seems to be that those whose names are written in the book of life, or who are truly the friends of God, would not be drawn away in admiration of the beast, or in rendering homage to it.

When they behold the beast that was, and is not, and yet is. That is, the power that once was mighty, that had declined to such a state that it became, as it were, extinct, and that was revived again with so much of its original strength that it could be said that it still exists. The fact of its being revived in this manner, as well as the nature of the power itself, seemed suited to excite this admiration.