Likutei Moharan 15:1/ליקוטי מוהר"ן ט״ו:א׳

1“You will be to Me a kingdom of priests and a holy nation. These are the words that you should speak to the Children of Israel.” (Exodus 19:6)

2Anyone who wants to experience a taste of the Or HaGanuz (Hidden Light)—i.e., the mysteries of the Torah that will be revealed in the Future—must elevate the aspect of fear to its source.