I take it you believe both Reform Jews and Lubavitchers are Jews. Other than
tenuous tribal kinship - and the Shema Yisrael, the beliefs are different - leading to different attitudes about (others)
and outcomes.
For example, Catholics are pretty different in their beliefs and practices than Pentecostals.
While Catholics accept on faith some portions of scripture, fundamentalists believe that everything written in the Hebrew Canon and the Gospel is literally factual.
OTOH most mainline practicing Christians (Episcopalians, Methodists, Presbyterians, etc.,) do not accept a literal interpretation of scripture - but rather use the scripture as a guide. They likely have no problem with evolution or climate change or other findings of science.
Fundamentalists are much better at promoting themselves than mainstream Christianity - especially among the non-college uneducated.
Fundamentalism avoids "weak" dependency on the "Spirit" and clings to text. In other words it puts intuition
and contemplation in the back seat. They're all about judgment. They're sure of themselves. They're prideful, yet dole out words of self deprecation. They engage in gossip and slander. They're idolaters (look how they worship Trump). I can't stand em as a group. I find
them incurious, dull and lacking in imagination. A bunch of mean spirited fuck-wits. Moreover, many of them I encounter in the South just use their religion as a reason to shit on other people which is the opposite of their putative "savior."