ואם תלכו עמי קרי ולא תאבו לשמע לי ויספתי עליכם מכה
Rashi explains keri, casually, as applying to one who is observant, yet his performance of mitzvos is, at best, erratic and haphazard. His attitude toward mitzvos is not one of obligation, but rather, of convenience and choice, sort of being in the “mood” of performing a mitzvah. Horav Moshe Shternbuch, Shlita, writes that when his Rebbe, Horav Moshe Schneider, zl, would read this pasuk, he would weep. He remarked that this pasuk refers to the Jew who fulfills mitzvos, who studies Torah, but it is not an obligation for him. He learns when he wants, attends a shiur at will….