Are you familiar with Justin Martyr @GodsGrace?
en.wikipedia.org
A second century Christian apologist who lived c. A.D. 100 - 165. He was a pagan philosopher who converted to Christianity.
“When Justin argues against Jewish monotheists in the Dialogue, he insists that there is a ‘second God’ … and that this is Christ.”
(Robert M. Grant, Jesus After the Gospels: The Christ of the Second Century, p. 65)
Justin is speaking with a Jewish monotheist, a man named Trypho, who does not believe that Jesus of Nazareth is the promised Messiah. I’m a Jewish monotheist who believes that Jesus of Nazareth is the promised Messiah. Otherwise, Justin is speaking to me today in his writing.
What did Justin think about Jewish Chritianity?
“Justin tolerated [Jewish Christianity] but did not regard as fully orthodox (Dialogue 45-47).”
(Ibid. p. 65)
“Fully orthodox” for Justin isn’t at all what is contained in the Nicene Creed.
A rhetorical question: Is Justin, who knew nothing whatsoever about the Nicene Creed, a Christian?
A second rhetorical question: Would a Jew who lived prior to the fourth century and knew nothing whatsoever about the Nicene Creed but believed that Jesus is the promised Messiah, be or not be considered a Christian?

Justin Martyr - Wikipedia
A second century Christian apologist who lived c. A.D. 100 - 165. He was a pagan philosopher who converted to Christianity.
“When Justin argues against Jewish monotheists in the Dialogue, he insists that there is a ‘second God’ … and that this is Christ.”
(Robert M. Grant, Jesus After the Gospels: The Christ of the Second Century, p. 65)
Justin is speaking with a Jewish monotheist, a man named Trypho, who does not believe that Jesus of Nazareth is the promised Messiah. I’m a Jewish monotheist who believes that Jesus of Nazareth is the promised Messiah. Otherwise, Justin is speaking to me today in his writing.
What did Justin think about Jewish Chritianity?
“Justin tolerated [Jewish Christianity] but did not regard as fully orthodox (Dialogue 45-47).”
(Ibid. p. 65)
“Fully orthodox” for Justin isn’t at all what is contained in the Nicene Creed.
A rhetorical question: Is Justin, who knew nothing whatsoever about the Nicene Creed, a Christian?
A second rhetorical question: Would a Jew who lived prior to the fourth century and knew nothing whatsoever about the Nicene Creed but believed that Jesus is the promised Messiah, be or not be considered a Christian?