There are two kinds of fear. We can see that with the fear of the Lord comes life, confidence, salvation, deliverance, plenty, the perfecting of holiness, the protection of us by angles, wisdom, and doubtlessly that is not all. (See the verses at the end)
We are commanded not to be fearful of those who can harm the body, but rather to fear God. (Matthew 10:28, 1 Peter 2:17, Revelation 21:8)
This idea of fearing the Lord is misunderstood by many. The only way to understand it is to read what the Holy Scriptures have to say about it.
It appears that the more we know of God and his attributes such as his Holiness, Omniscience, Omnipotence, Omnipresence, Immutability, Sovereignty, Justice, Mercy, Faithfulness and so on the more we fear him. Fearing God also leads to humility (because we see ourselves for who we are), and Love toward God, because we see how much he has done for us despite our foolishness, stubbornness, and evil desires (our depravity). Both the fear and love of God lead us to obey him. Is not this also what 1 John 2:4 is saying, that as we know God we obey him? Knowing him leads us to both fear and love him which leads us to obey him.
Part of this fear is an awe of how great and marvelous God is. It is a result of understanding a mere shadow of his mighty power, of getting a small glimpse of how his ways are higher than our ways. (Isaiah 55:9, Psalm 33:8)
And yet in all his greatness he is not so far removed from us that he does not care for us, but rather he even cares much for the birds as we can see in Deuteronomy 22:6. If he cares this much for the birds imagine how much more he cares for us. After all he sent his only begotten Son to die for us that we may be saved! His Only Son to be the propitiation for our sins! (1 John 4:10) And as Jesus himself said in Matthew 6:26, “Behold the fowls of the air: for they sow not, neither do they reap, nor gather into barns; yet your heavenly Father feedeth them. Are ye not much better than they?”
In John 14:15 Jesus says “If you Love me, keep my commandments.” This is followed later in verse 21 with “He that hath my commandments, and keepeth them, he it is that loveth me: and he that loveth me shall be loved of my Father, and I will love him, and will manifest myself to him.” This is also similar to that said in 1 John 5:3 and 1 John 2:5.
In order to know, fear, love and obey God we must acquaint ourselves with him. How do we do that? In Job 22:21-23 we see that we are to lay up his words in our heart. If we lay up his words in our heart goodness shall come to us, and iniquity shall be far from us.
Acquaint thyself with the Almighty!
“In the fear of the LORD is strong confidence: and his children shall have a place of refuge. The fear of the LORD is a fountain of life, to depart from the snares of death." - Proverbs 14:26-27
“I sought the LORD, and he heard me, and delivered me from all my fears. They looked unto him, and were lightened: and their faces were not ashamed. This poor man cried, and the LORD heard him, and saved him out of all his troubles. The angel of the LORD encampeth round about them that fear him, and delivereth them. O taste and see that the LORD is good: blessed is the man that trusteth in him. O fear the LORD, ye his saints: for there is no want to them that fear him.” - Psalm 34:4-9
“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.” - 2 Corinthians 7:1
“So that we may boldly say, The Lord is my helper, and I will not fear what man shall do unto me.” - Hebrews 13:6
“In God I will praise his word, in God I have put my trust; I will not fear what flesh can do unto me.” - Psalms 56:4
“And unto man he said, Behold, the fear of the Lord, that is wisdom; and to depart from evil is understanding.” - Job 28:28
“Yea, though I walk through the valley of the shadow of death, I will fear no evil: for thou art with me; thy rod and thy staff they comfort me.” - Psalms 23:4
“Who shall not fear thee, O Lord, and glorify thy name? for thou only art holy: for all nations shall come and worship before thee; for thy judgments are made manifest.” - Revelation 15:4
For more on fear see Romans 3:15-18, Psalms 33:18-22, Psalms 103:11, Psalms 86:11, Psalm 96:9, Psalm 27:1, Luke 12:4-5,Leviticus 19:14, Leviticus 25:17, Proverbs 1:7, Ephesians 5:21, and etcetera.
See the Hymn "Amazing Grace"