Reg. the difference between Judaism and Christianity:
(le-havdil), A analysis (found here:
www.netzarim.co.il (that is the only legitimate Netzarim)) of all extant source documents and archaeology using a rational and logical methodology proves that the historical Ribi Yehosuha ha-Mashiakh (the Messiah) from Nazareth and his talmidim (apprentice-students), called the Netzarim, taught and lived Torah all of their lives; and that Netzarim and Christianity were always antithetical.
The mitzwot (directives or military-style orders) in Torah (claimed in Tan’’kh (the Jewish Bible) to be the instructions of the Creator), the core of the Judaism, are an indivisible whole. Rejecting any one constitutes rejecting of the whole… and the Church rejected many mitzwot, for example rejecting to observe the Shabat on the seventh day in the Jewish week. Examples are endless. Devarim (“Deuteronomy”) 13.1-6 explicitly precludes the Christian “NT”. Devarim 13:1-6 forbids the addition of mitzwot and subtraction of mitzwot from Torah.
Ribi Yehoshuas talmidim Netzarim still observes Torah non-selectively to their utmost today and the research in the previous mentioned Netzarim-website implies that becoming one of Ribi Yehoshuas Netzarim-followers is the only way to follow him.