In his book The Goal of the Wise, Abdullah Hashem writes the following about the founder of the religion of Manicheism - a now mostly defunct religion which had some success in antiquity:
The Goal of the Wise - Chapter 31, pg. 402-403
Contrary to orthodox Christian belief, Jesus (PBUH) married Mary Magdalene, and she became pregnant with a son. That son, Mani, would grow up to be taught by Jesus (PBUH) and sent forth as a Messenger from Jesuit and Mohammedan Covenants. Thus, this is the true story of the lost years of Jesus Christ (PBUH).
Here, Hashem teaches that Mani (216-274 CE) was the son of Jesus of Nazareth and Mary Magdalene. In reality, Mani lived about 200 years after Jesus of Nazareth was killed, and had direct dealings with Iranian kings who lived during that time (Shapur I, Hormizd I, Bahram I), meaning that multiple streams of uncontroversial secular history would need to be entirely falsified in order for Hashem's timeline to not be complete nonsense.
He also says the following, referencing the Quran's apparent teaching in Surah 4:157 that Jesus was not actually crucified:
The Goal of the Wise - Chapter 31, pg. 405
Mani was actually the look-alike who was crucified in place of Jesus (PBUH). He reincarnated back into this world as the son of Jesus (PBUH).
Abdullah's timeline for these two figures is kind of confusing, but he is teaching here that Mani lived contemporaneously with Jesus, and then was later reborn as Jesus's own son. When someone makes a claim like this, which overthrows all known history of Christianity, Manicheism, Israel, and Iran, the onus is on them to support their claim. Hashem does not, preferring the reader take his word for it, as he desperately tries to link two religions (Christianity and Manicheism) which in reality were radically different from one another, and separated by centuries, and hundreds of miles.
In The Goal of the Wise, Hashem quotes a large section from the Gospel of Barnabas, attributing the words to Jesus of Nazareth (Chapter 3, pg. 31-33). In reality, the Gospel of Barnabas is known to be a 13th or 14th century fabrication, composed in Spanish or Italian, well over 1,000 years after the real person Barnabas died. It has nothing to do with Jesus of Nazareth, it denies that he was the Messiah (Chapter 42, 82, 97, 198), which Hashem affirms, and it came out of a Muslim milieu, as it has Adam read the Shahada (Chapter 39, 41).
Anyone quoting the Gospel of Barnabas to substantiate their doctrines is not serious about history or honesty before God. They are merely using whatever they can to support their beliefs, even if it is obviously forged.
Scores of pages in Hashem's attempt at religious scripture have claims which could be dissected like the two above, and debunked. Most of his followers have probably never even read any of it, however, so it is unlikely that covering claim after claim would achieve much more than simply ending with the two examples above, and inviting anyone to read and examine the book for themselves if they still have any doubts. The entire work reads as unhinged, conspiratorial, and severely lacking in any type of critical review or attempt to seriously justify its claims.
Abdullah Hashem insults all of his followers in a way that shows that he has no respect for them whatsoever as thinking, rational fellow human beings. He will write absurd, grandiose lies about virtually all of secular and religious history, provide none of the evidence required to demonstrate his claims, and then expect them to believe it because he said so. He is not hard to see through, and in the coming years, many of those who he told his outrageous lies to will research for themselves, and inevitably see him for the charlatan he is. Hopefully this article contributes to that.