There are a number of problems with your post. The first is I can find no clear reason why what you posted should in any way be considered a response to the post you cite.
]Karen Armstrong in her “A History of God” makes the point that Jews are expected to follow the Law as presented in the Torah.
I never heard of her. Why should I listen to her?
There are 613 commandments (mitzvot) that Jews must follow to avoid sinning.
That is a number, but consider the number of laws and regulations we live under now: a lot more
Human nature being what it is, it is likely that no Jew can follow all 613 mitzvot.
Here your logic breaks: in the preceding, “it is likely” and you conclude from that via the 'therefore" that it must be so. This does not logically follow.
Therefore, Jews in general are sinners. They are pardoned for their sins through the process of atonement.
In the days of Jesus, whose mother Mary was a Jew, the Laws of the Torah were in effect. Thus, Jesus and Mary must have been sinners just like the rest of the Jews.
Here you have moved from your generality “Jews in general” to two Jews in particular. This is another logic break.
It is also clear that you seem unaware of the debate about this on the thread - and the unspoken assumption, based on Scripture and Church teaching, that neither was a sinner. Jesus as the spotless lamb of God, innocent of sin, who made peace with God through His blood, the Son of God without sin, is absolutely foundational to Christianity. How could you miss that and so blithely state that He is a sinner?