Likutei Moharan 14:7/ליקוטי מוהר"ן י״ד:ז׳

17. And the essential thing is that a person sincerely honor those who fear God. As our Sages taught: Of those things which are given over to [i.e., hidden in] the heart, it is said, “And you shall fear your Lord!” (Kiddushin 32b). Therein lies the essence of glory, as in (Isaiah 29:13), “With their lips they honor Me, but their hearts they have distanced from Me.”