I can't imagine how Gentiles must feel reading a commentary on the heretical gnostic sect 'the Marcosians' but I can tell you how a Jew who was brought up with a knowledge of kabbalah. It is so annoying it drives me crazy.
The presuppositions of Gentiles at work as they search for the 'Judaism' from which 'Jewish Christianity' originated are so utterly obvious. First of all, we are told that the Jews 'always' believed 'only' in the Creator the God of Israel.
Nevertheless these same genius can't explain why the same 'strictly monotheistic Jews' say the trisagion? Don't these people actually read the literature of the Jewish mystical tradition?
No, probably not. They are - as should be obvious by now - DELIBERATELY manufacturing an entirely ARTIFICIAL understanding of 'the Jewish origins' from whence their own 'strictly monotheistic' Jewish sect Christianity came.
That is how they even dare to DREAM of a scenario that even a single Jew in history could have mistaken someone like Jesus for THE Messiah. But I digress ...
The bottom line is that if we were looking for a Jewish context out of which Christianity eventually developed the sect of the Marcosians is EXACTLY what we should expect - viz. a specifically Alexandrian Jewish community which can account for many of the core ideas of the religious tradition (especially 'the Logos).
Stephan Huller has had a life long interest in religion and spirituality 
dating back to conversations with his grandfather, Gaston Frank. "He said we represent one of the last descendants of the Frankist Jewish faith in the world," he muses. "I grew up thinking that our family was something like the Last of the Mohicans."