Q. Is a person considered a kofer (non-believer and thus makes yain nesech), if he does not accept the following: that a reshus hayachid (private domain for the purpose of the prohibition of carrying object on Shabbos) can be created by invisible walls via gud asik machitza (a partial partition that can be considered as a virtual full partition) and punishable by the death penalty if he does hachnasa (transgresses the biblical prohibition)?
A. Horav Shlomo Miller's Shlit'a opinion is that you are more likely dealing with an uneducated am haaretz, that doesn't know the intricacies and complexities of the halachos of Shabbos. One should make an effort to teach them to him. It is quite plausible that learning them will induce him to keep all the aspects of Shabbos properly. Since he does otherwise keep Shabbos and is only ignorant of some halachos, he is not a mumar.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller's Shlit”a
Important Numbers
