I think this is really interesting. The "fear of the Lord" can be somewhat of a mystery. 
It is mentioned so many places in the Bible, and in so many different ways. Today, the Holy Spirit really cleared this one up for me.  Using God's Word, of course, and through a really neat progression of scripture!  I'd like to share this with you. (In many cases, I did not write down the entire Bible verse. Just enough to share what I was shown.) Bear with me until I will pull them all together, okay?!

So, what is the "fear of the LORD"?

Proverbs 8:13  "The fear of the LORD is  to hate evil..."

Psalm 111:10  "The fear of the LORD is  the beginning of wisdom..."

Pro 1:7 "The fear of the LORD is  the beginning of knowledge..."

Job 32:8  "But there is a spirit in man: and the inspiration of the Almighty giveth them understanding."

Job 28:28  "...Behold, the fear of the LORD, that is  wisdom; and to depart from evil is  understanding."

Pro 3:7 "Be not wise in thine own eyes: fear the LORD, and depart from evil."

Pro 9:10 "...  and the knowledge of the holy is  understanding."

Holy?  Ps 99:9 "...for the LORD our God is holy."
Isaiah 6:3 "...Holy, holy, holy, is the LORD of hosts..."
Revelation 15:4  "Who shall not fear thee, O LORD, and glorify Thy name? For Thou only art holy..."

Luke 24:45  "Then opened He their understanding, that they might understand the scriptures,"

Pro 2:6  "Then shalt thou understand the fear of the LORD, and find knowledge of  God."

Yes!, the Beginning!  Fear of the LORD - Hate evil - begin wisdom - begin knowledge - receive understanding -  fear the LORD - get wise - depart from evil - get understanding - knowledge of the Holy One -  understand the scriptures - "Then shalt thou understand the fear of the LORD, and find knowledge of  God." Pro 2:6  Yes, the Beginning AND the End!  Jesus IS the Beginning and the End - the "Alpha and Omega"!  (Rev 1:8)  Wow!

Acts 9:31 "Then had the churches rest throughout all ... and were edified; and walking in the fear of the LORD, and   in the comfort of the Holy Ghost..."  Again, wow!

John 14:26-27 Jesus said, "But the Comforter, which is the Holy Ghost, whom the Father will send in My name, He shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you. Peace I leave with you, My peace I give unto you: not as the world giveth, give I unto you, Let not your heart be troubled, neither let it be afraid."

Comfort!  Because actual "fear" is not what God want us to live in. Luke 1:70-75  "As He spake by the mouth of His holy prophets, which have been since the world began: That we should be saved from our enemies, and from the hand of all that hate us; To perform the mercy promised to our fathers, and to remember His holy covenant; The oath which He sware to our father Abraham, That He would grant unto us, that we being delivered out of the hand of our enemies, might serve Him without fear. In holiness and righteousness before Him, all the days of our life." Amen!!

Conclusion: 2 Colossians 7:1 "Having therefore these promises, dearly beloved, let us cleanse ourselves from all filthiness of the flesh and spirit, perfecting holiness in the fear of God."  Hebrews 12:4  "Follow peace with all men and holiness without which no man shall see the LORD."  1 Peter 1:16  "Because it is written, Be ye holy; for I am holy."  And how do we do this?  Well, we can start at the very beginning -  hating evil!  Proverbs 8:13  "The fear of the LORD is  to hate evil............."  Pro 2:6  "Then shalt thou understand the fear of the LORD, and find knowledge of  God."

2 Peter 3:11-12, 14  "Seeing then that all these things shall be dissolved, what manner of persons ought ye to be in all holy conversation and godliness, Looking for and hasting unto the coming of the day of God... Wherefore, beloved, seeing that ye look for such things, be diligent that ye may be found of Him in peace, without spot, and blameless." 

Walking in the fear of the LORD!