Musar zu Mischlej 15:16

Now we see that everything depends upon Fear of Heaven, and that the whole Torah is of no use to a man unless it is accompanied by Fear of Heaven, which is the very peg upon which everything hangs. And it is Fear of Heaven alone that stands by a man forever and ever. And thus did David testify, "The fear of the Lord is clean, enduring for ever" (Ps. 19:10). And thus also King Solomon testified and said, "And God hath so made it, that men should fear before Him (Eccl, 3:14). And it is written, "Better a little with the fear of the Lord, than great treasure and turmoil therewith" (Prov. 15:16).