I have to wonder about the author of that site and whether he was using for "scripture" something taken from what he thought were the Akashic Records. Ha ha ha.
For example, it's a common misconception that the passage in Genesis (6:1-3) says that the offspring of "the sons of G-d" (whatever that means) and the "daughters of men" were giants. It doesn't say this. The passage remarks that there were giants in those days. It then says (v 3), referring back to verse 2, that in addition to there having been giants in those days, the offspring of the SOG and DOM became mighty men of reknown. It doesn't, however, say that the MMOR were giants. What the text actually says, though, is often the least concern of many.
The biblical account then continues by saying that the offspring of the Sons of God and the daughters of men were "the giants who were in the earth in those days." So numerous did these giants become that they were a threat to the survival of the patriarchal race. Accordingly, the scripture tell us, God gave Enoch a magical or miraculous sword, called the "Sword of Methuselah," with which to slay them in a great purge. The race of giants then dwindled and finally became extinct, Goliath being the last of his race, slain by young David, future King of Israel, sometime prior to 1,000 B.C.
Sentence 1: The passage in question doesn't say this.
Sentence 2: Scripture (at least that associated with Genesis, ie., the Bible, the Torah) doesn't say this.
Sentence 3: Ditto. No sword. No purge.
Sentence 4: Ditto.
Sentence 5: Ditto. Goliath from Gath was a Philistine, hardly the last of his race.
Apparently Goliath had at least one big brother, Lahmi, who was killed, subsequent to Goliath's death at the hand of David, by a guy from Bethlehem. The only one referred to in scripture as being a giant (of the famed Anakim) and the last of his kind was Og king of Bashan (Deut 3:11). This was well over a couple of centuries before King David. Whatever the cause of Goliath's large condition, it wasn't, at least according to the Bible, because he was one of the Anakim.
Funny, in this context, that those who maintain that Goliath was the last of his race of the giants and that the giants referred to as the Anakim in Deuteronomy (B) were the same ones referred to in Genesis 6:1-3 (A), don't ask the question of where these giants came from if all humans alive at the time of B were descendents of the eight who made it through the flood as sole representatives of the human race, the giants A being antediluvian. Their answer? 1. They weren't human and only humans were in the ark? But they were called, according to these people, mighty men of reknown, the offspring of humans and "the sons of G-d". They aren't described as 'inhuman'. 2. These are all mythological tales and we can't attest to the complete facticity of any particular one? If so, then how to attest to the facticity of any? They become, then, simply the building blocks from which to erect entertaining tales about such things as the Sword of Methuselah. Meanwhile, people who have no little or no knowledge about the Bible hear these things, see the absurdities, and then assume that it's the Bible that is the source and go on to ridicule it on places like sites on the skeptic ring for saying things it never did. It's disheartening, though hardly surprising.
FWIW
Genesis 6:4
There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bare children to them, the same became mighty men which were of old, men of renown.
Numbers 13:33
And there we saw the giants, the sons of Anak, which come of the giants: and we were in our own sight as grasshoppers, and so we were in their sight.
Deuteronomy 2
10 The Emims dwelt therein in times past, a people great, and many, and tall, as the Anakims;
11 Which also were accounted giants, as the Anakims; but the Moabites called them Emims.