In regards to the conflict between Ruchniyus (Spirituality) and Gashmiyus (Physicality)
It should be known and familiar to nearly everyone who is involved in study of Torah that there is a great deal of machlokes (conflict/disagreement) in regards to how one should approach gashmiyus in Yiddishkait. You have one side that advocates for essentially complete asceticism and the other side promotes a general attitude of relative permissiveness, albeit within the boundaries of halocho. This could easily lead to a lot of confusion and internal conflict, so I’d like to address this complicated inyan just a little. This is not meant to be a complete explanation and teirutz to all questions, just a general explanation as to a proper path.
If you look in the Ramchal, particularly in Derech Hashem and Mesilas Yeshorim, we are met with a concept of gashmiyus that essentially says that corporeality is darkness and evil, all this ultimately does is serve to test the neshomoh. Then you come to the general approach of chassidis which, at least on the surface, says the exact opposite; that the body and all physicality is meant to be used for avodas Hashem within the bounds of halocho. However if you look in the Tanya, the Baal HaTanya has a statement in the 32nd perek that one should become disgusted with his body and bodily desires in order to feel only the spiritual joy, which is easy to accomplish through mitzvas v’ohavto l’reaiacho k’mocho (loving your fellow as yourself), in his words in short. The old Skverer rebbe zt’l used to spoon salt into every dish he ate, presumably in order that the food should be disgusting and lacking in any taste, so his eating should only be l’shem Shomayim. Such a level is very high, and pertains to those who merit to be on such a level of holiness that they don’t care about tastes of food whatsoever. So how can we achieve some level of balance in regards to this avodah as simple people?
Essentially, we all have to realize there are sparks of holiness concealed within every single thing in the universe. Every tree, grain of salt, stone, animal, and person is full of holiness sourced straight from the One Source, Hashem, Ain Sof. This realization can be difficult to comprehend at all times, but it is something to work on, which can be accomplished through visualizing the shem Havayah (Yud with He along with a Vuv and a Heh) on all things, as explained in Sefer Reishis Chochmah. All things are sealed with that special Shem, the ineffable name, which means that they are sealed and infused with Kedusha. As this avodah is worked on, it is important to work on balance. The Mesilas Yeshorim brings that one should remove everything from their life that takes away from avodas Hashem, in the chapter on Zehirus (Vigilance), and goes even further to say that everything unimportant in serving God should be removed from your life, leaving only that which helps you. The way this was explained to me, and makes sense al pi chassidus, is that this degree of removing things refers to those that do not help you serve Hashem with simcha. The Ramchal states at various points, but especially in the perek on Chassidus, that the entire purpose of a Yid is to delight in the splendor of the Shechinah, and bask in Hashem’s radiance. Every action at that point is to be devoted entirely to serving Hashem, with nothing extraneous.
One way it is possible to understand this through the lens of the Toras HaBaal Shem Tov is that the goal of our learning Torah and our mitzvos is to purify us to the degree that all of our actions are holy. Rather than this meaning that we should fast and become completely divorced from gashmiyus to the highest degree, we have a heter of sorts to engage with the physical world with a spiritual focus in order to create a Dirah B’Tachtonim (Dwelling Place Below) for Hashem’s Light, so to speak, and hence elevate the corporeal world to Divinity. Per example, rather than focusing on the taste of a food and what pleasure it gives to the body, the focus should be on thanking Hashem for the experience and through this, elevating the sparks of holiness to their proper home. Instead of feeling guilt for being created as Hashem created you, you should instead thank Hashem for granting you the special task as a human made of flesh and blood to make Tikkunim in this world, and have the special privilege to consciously experience the Divine at all times that you can attain to.