I'm not anti Fringe theorizing. Every lie has some truth in it. I agree 100% with the arguments against it being built by Kufu. I own Ken Klein's The Pillar of Enoch, it's a fun documentary (but even when I agreed with the theory I wish he'd have left the UFO stuff out of it). It definitely seems to be older then Kufu's time.
Because of my view on The Flood, that there was more to it then just water going up and coming down, I'm not as inclined to agree it could have been a Pre-Flood structure.
I recommend the Great Pyramid part of Chris White's Ancient Aliens Debunked. It was built by Human beings, maybe it's true the Giza Pyramids weren't tombs like the others, but they weren't the product of an Abrahamic Faith.
One of the main popularizers of the Great Pyramid being a Godly structure theory was Charles Taze Russell, founder of the Watch Tower society. Russell was also a Freemason and not a Casual one. He was buried at an important Masonic Cemetery with a huge All Seeing Eye Pyramid structure in it. Other early founders of the theory include John Taylor, who I've fond no documentation of being a Freemason but was interested in a lot of Neo-Pagan stuff. Then there was Charles Smyth who was also into British Israelism, another doctrine Freemasons like especially the Orange Lodge.
The specific claim of it being built by Enoch has it's origins in Hermetic tradition saying the Pyramids were build by Hermes-Thoth Trismegistus, and them Arabic Alchemist tradition identifying Trismegistus with Enoch. And that tradition in turn influencing Masonic lore.
Linking the Pyramid to Enoch is an idea that is vital to Masonic lore, among what they borrowed via the Alchemists from Arabian folklore. Enoch is important to Masonic lore which is why it was Masons who rediscovered the Book of Enoch, Just look up the Royal Arch of Enoch.
People involved in this "Christian" Pyramidology often argue that New Jerusalem/Yahweh-Shammah could be Pyramid shaped rather then a Cube, which they say is the only way it makes sense for a four sided structure to have a single cornerstone.
It is true that "Corner" is not the best translation of the Hebrew Term, in fact pinnacle could work better. But that word when used in connection with The Temple seems to refer to a pinnacle above the gate of The Temple, not the Capstone of a Pyramid like structure.
The passage from Josephus cited (Antiquities of The Jews Book 1 Chapter 2 Section 3) about the Pillars of Seth is merely describing simple pillars with info written on them. The Giza pyramids have no engravings which is the whole foundation of thinking they have a separate purpose from other Egyptian Pyramids to begin with. And saying Siriad means Egypt is a very recent claim, that term was commonly understood in antiquity as referring to Syria.
But I think Siriad might actually come from the Hebrew place name rendered Sarid in the KJV of Joshua 19:10-12 in the allotment of Zebulun. Deuteronomy 33:18-19, Moses prophesying of Zebulun with Issachar dwelling among them, refers to "treasures hid in the sand".
Isaiah 19 is a Prophecy, it's about the Future not the past. The first 17 verses were fulfilled in the 20th Century.
Isaiah 19:19 is the verse in question.
In that day shall there be an altar to the LORD in the midst of the land of Egypt, and a pillar at the border thereof to the LORD.The claim is made that the Great Pyramid is at the border between Upper and Lower Egypt allowing it to fit both these descriptions. That is an error.
Where exactly the border was isn't entirely clear, but Lower Egypt consistently always included the entire Delta region and Giza is firmly within the Delta.
Because of the nature of Hebrew poetic expression it is hypothetically possible Isaiah 19:19 could be describing the same thing in two different ways. But equally possible it's describing two similar yet distinct things. The question is, is it plausible for the Hebrew terms rendered "Altar" and "Pillar" here to refer to the same thing. There doesn't seem to be any other Hebrew precedent for it.
An Altar is pretty consistently a place where sacrificial offerings were made. While a Pillar is just a simple stone structure made in honor of God that isn't an Idol (this Hebrew word is sometimes translated Idol when in reference to things honoring false gods). Since there is no way burnt offerings were made in or on the Great Pyramid, clearly only the latter could even remotely describe the Great Pyramid. Yet as I showed it is only the former that could fit it's location.
Exodus 24:4 is another verse that uses both these same Hebrew words together, clearly they are separate things.
The way people describe the Great Pyramid lay out as fitting Biblical symbolism is very manipulative, you can do it with anything if you try hard enough. As Chuck Missler likes to say "If you torture the data long enough, it will confess to anything".
Two Jewish Temples were built in Egypt in ancient history. Neither of those I believe is the fulfillment of this Prophecy. But if you want to use structures that have already existed as a model for how this Millennial picture of Egypt might look, they are far more appropriate.
First there was the one on Elephantine Island. I agree with Bob Cornuke that The Ark of the Covenant and The Mercy Seat were housed there for awhile on their way to Ethiopia. It is pretty close to where the traditional southern border of Egypt usually was.
Then there is the Leontopolis Temple build by Onias IV after around the time of the Maccabees. This location could fit the Midst of the Land of Egypt. And Onias attempted to present it as fulfilling Isaiah 19:18-19 when he built it.
Wikipedia is of course quite skeptical of Josephus. I am in many places too, but I think everything they criticize in the Onias Letter section is still possible. As for the discrepancy between what's said in Wars and Antiquities, in Antiquities Josephus fully explains at the beginning he shall be correcting mistakes he made in the earlier Wars.