After time, the nationalist idea gave birth to an offshoot – "religious nationalism". The name alone indicates that the term “religious” alone is incomplete unless accompanied with the term “nationalist”. This name alone is kerfirah [apostasy] against one of the fundamentals of faith, that “Toras Hashem temimah”, i.e. the Torah is lacking nothing and has no defect… If the idea of nationalism is avodah zarah [idolatry], the idea of religious nationalism is avodah zarah b’shituf [joining idol worship with worship of G-d].R’ Kook, Orot Yisrael, ch. 6
The practical nationalistic drive of the Jewish people is just the external manifestation (levush) of its inner spiritual drive. The latter is the light and soul of the former. Both stem from the Living G-d, and from the spring of truth and belief.