In the Hebrew Bible, these three words, while not perfectly interchangeable, are sometimes used similarly. Both ruaḥ and n’shamah check with the life span breathed by God into humankind and are conjoined in the same verse when Genesis speaks of nishmat ruaḥ ḥayyim, “the n’shamah of the ruaḥ of life.” Ruaḥ and nefesh frequently designate a person’s mental and emotional state and constitution, or what it is that we might call today his or her “self,” as in verses like “And it happened each day that he [Pharaoh] was troubled [va-tipa’em ruḥo, literally, “his spirit was excited”], or even the Psalmist’s “Thy comforts delight me [nafshi].” N’shamah tends to be a phrase for the life of human beings generally or for any living being, as in “And Joshua smote all the country considering the hills . . . and destroyed all that lived [literally, “every n’shamah”].”
However there is no word in the Hebrew Bible equivalent to “spiritual” or “spirituality.” Neither is there one within the Talmud, wherein, however, the word n’shamah represents a meaning of that sort in our English “soul”—a divine substance or presence that inhabits and animates our body while becoming endowed by us with a character uniquely its own. It is really an concept that the Judaism considering the first centuries of the Common Era shared with Christianity and various Gnostic and Neoplatonic groups; whether we know in a soul or otherwise, our contemporary notion of spirituality falls back on it.
However whereas Christianity had a term for “spiritual” from its inception—Paul, in his New Testament epistles, uses the Greek word pneumatikos, which the Latin church fathers translated as spiritalis—rabbinic Judaism, precisely because it resisted stressing the inwardly “spiritual” life at the expense of the outward lifetime of God-given commandments and their observance, did not develop its equivalent term of ruḥani till the Dark ages.
Moreover, ruḥani in medieval Judaism did not mean the same thing as “spiritual” did in Christianity or does today. Both medieval Jewish philosophy and Kabbalah divided a person’s psyche into three parts: the nefesh, which was liable for biological functions; the ruaḥ, that was accountable for intellectual ones; and of course the n’shamah, which was what nowadays could be thought of as a person’s “spiritual” side. In modern Hebrew, too, ruḥani is most often better translated as “intellectual” than “spiritual.”
In East European Hasidism, it s correct, rukhniyus (the Ashkenazi pronunciation of ruḥaniyut, in which the Hebrew suffix –ut is parallel towards the “-ity” of “spirituality”), instead of gashmiyus or “materialism,” was sometimes used as “spirituality” is in English today. However there are other, more common terms in Ḥasidism for a state of religious inwardness and closeness to God, and none among the ever posited a dichotomy amongst the latter and the outward practice of Jewish ritual, prayer, and custom. Quite the opposite: outward practice was a precondition for inward “spirituality.”