The Lord tells those who fear Him or are His redeemed to say the following:

“Let those who fear the LORD now say, ‘His mercy endures forever.’”
    (Psalm 118:4 NKJV)

“Oh, give thanks to the LORD, for He is good!
For His mercy endures forever.
Let the redeemed of the LORD say so,
Whom He has redeemed from the hand of the enemy,”
    (Psalm 107:1-2 NKJV)

“You who fear the LORD, praise Him!
All you descendants of Jacob, glorify Him,
And fear Him, all you offspring of Israel!”
    (Psalm 22:23 NKJV)

“Then a voice came from the throne, saying, “Praise our God, all you His servants and those who fear Him, both small and great!” And I heard, as it were, the voice of a great multitude, as the sound of many waters and as the sound of mighty thunderings, saying, “Alleluia! For the Lord God Omnipotent reigns!”
    (Rev 19:5-6 NKJV)

What does it mean to “fear the Lord?” This is an oft-asked question. The best place to find out is directly from Scripture. Let's take a look at what the Word of the Lord says about the fear of the Lord.

“Come, you children, listen to me; I will teach you the fear of the LORD. Who is the man who desires life, And loves many days, that he may see good? Keep your tongue from evil, And your lips from speaking deceit. Depart from evil and do good; Seek peace and pursue it.” (Psa 34:11-14 NKJV)

“The fear of the LORD is to hate evil; Pride and arrogance and the evil way And the perverse mouth I hate.” (Prov 8:13 NKJV)

“"The fear of the LORD is the beginning of wisdom, And the knowledge of the Holy One is understanding.” (Prov 9:10 NKJV)

“The fear of the LORD is the beginning of wisdom; A good understanding have all those who do His commandments. His praise endures forever.” (Psa 111:10 NKJV)

“The fear of the LORD is the instruction of wisdom, And before honor is humility.” (Prov 15:33 NKJV)

Let us also take a look at a related verse that talks about loving the Lord.

“If you love Me, keep My commandments. ‘And I will pray the Father, and He will give you another Helper, that He may abide with you forever;’” (John 14:15-16 NKJV)

I think that we can derive from these scrptures that fearing the Lord and loving the Lord are evidenced in our life by our obeying God, by hating evil and desireing to follow Him. I am not saying that this is the method by which we obtain salvation. For salvation is a free gift of God for those who believe through faith.

“For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast. For we are His workmanship, created in Christ Jesus for good works, which God prepared beforehand that we should walk in them.” (Eph 2:8-10 NKJV)

“But to him who does not work but believes on Him who justifies the ungodly, his faith is accounted for righteousness ” (Rom 4:5 NKJV)

But, to fear the Lord means to understand His divine holiness and power. To realize what He has done for us through His grace and mercy. And our response to that should be to honor Him and obey Him. If we try to do that under our own power we will often fail. But note the second portion of the above scripture from John 14:15-16. Jesus indicates that He will send us a “Helper.” The Helper is the Holy Spirit, who will give us the power to live a life pleasing to God. How wonderful God is to us! Even the power to please Him, is a gift (grace) from God.