Eighty-one times throughout Scripture — from Genesis to Revelation — God says, “Do not be afraid.” 
Why? What is it about fear that is so important for us to overcome that God would say to us eighty-one times?
I decided to examine each of the instances in which this phrase appears in Scripture. In doing so, I came to this conclusion:
It is important to God that we not fear because God — the One who created us — who wired our minds and our emotions — knows that the root of our fear is doubt.
Let me say that again: The root of fear is doubt.
This is our life experience from when we are very young.
When we are very little and we’ve been tucked in bed at night:
It’s dark. “Mama, are you still there?”
When we are home alone and a strange noise startles us:
What was that noise? “Is someone there?”
When we are walking through the Valley of the Shadow and it feels like the darkness of life will never end:
Why is this happening to me? “God, are you there?”
The root of fear is doubt.
When we are afraid, we question whether the constants in our life are still there to protect us. We wonder if we have been abandoned and if we will have the strength or the bravery to confront whatever may lie in wait for us around the corner.
God knows that in our fear, we will doubt. And ultimately, we will doubt Him. We will doubt His goodness. We will doubt His faithfulness. And when we doubt Him, we lose our anchor; we lose the footing on our firm foundation.
Knowing we need God as our anchor, He exhorts us, “Do not be afraid.”
But why — why should we trust Him? Why should we not be afraid?
There is an interesting pattern that emerges when you examine each of these verses (see PDF attachment below):
In nearly every instance that God tell us, “Do not be afraid”, I observed that God does not affirm us in our fear (As in, “Hey, you can do this!” or “You are capable of facing this fear!”).
No. In nearly every instance of the phrase “Do not be afraid,” God affirms himself :
“Do not be afraid … I am your shield.” (Genesis 15:1)
“Do not be afraid … God has heard you.” (Genesis 21:17)
“Do not be afraid … I am with you.” (Genesis 26:24)
“Do not be afraid … God has come.” (Exodus 20:20)
“Do not be afraid … The LORD himself will fight for you.” (Deuteronomy 3:22)
“Do not be afraid … The LORD your God goes with you.” (Deuteronomy 31:6)
“Do not be afraid … The LORD your God will be with you wherever you go.” (Joshua 1:9)
“Do not be afraid … The battle is not yours, but God’s.” (2 Chronicles 20:15)
“Do not be afraid … I will save you.” (Isaiah 43:5)
“Do not be afraid … I have come.” (Daniel 10:12)
“Do not be afraid … Jesus said. (Matthew 10:26)
“Do not be afraid … Your prayer has been heard.” (Luke 1:13)
“Do not be afraid … My peace I give you.” (John 14:27)
“Do not be afraid … The Lord is my helper.” (Hebrews 13:6)
“Do not be afraid … I am the First and the Last” (Revelation 1:17)
So, first and foremost: why should we not be afraid? Not because we are capable of conquering our fear on our own, but because God is capable of conquering our fear; because God is for us; and because God is God!
The next observation I make is that as we trust in God because He is God, He does not expect us to do nothing. He does not expect us to be passive in our troubles. No. In many of these exhortations to not be afraid, once He has affirmed himself, He also gives us a directive to take action. Not just any action, mind you, (since actions we are likely to take in the midst of our fear and doubt often come from our irrational brain center — but specific action that He directs from Scripture:
“Stand firm.” (Yes, standing firm is an action — it requires intentional assertion.) (Exodus 14:13)
“Go up and take possession.” (Deuteronomy 1:21)
“Be strong and courageous.” (Deuteronomy 31:6)
“Peace!” (Yes, the exclamation point is there in the verse!) (Judges 6:23)
“Serve the Lord with all your heart.” (1 Samuel 12:20)
“ Settle down; serve…” (2 Kings 25:24)
“Take up your positions; stand firm. Go out and face them.” (2 Chronicles 20:17)
“Be careful; keep calm.” (Isaiah 7:4)
“Lift up your voice with a shout, lift it up!” (Isaiah 40:9)
“Set your mind to gain understanding; humble yourself before the Lord.” (Daniel 10:12)
“Be strong now; be strong.” (Daniel 10:19)
“Let your hands be strong.” (Zechariah 8:13)
“Go and tell.” (Matthew 28:10)
“Keep on speaking.” (Acts 18:9)
“Fall at his feet.” (Revelation 1:17)
“Be faithful.” (Revelation 2:10)
So, quick summary of what we are to do up to this point when we are afraid:
- Rest in the affirmation of God
- Take Action as He directs it in Scripture
And finally, as part of the pattern God establishes when He tells us to not be afraid, I observe that God often offers a promise:
“I will bless you.” (Genesis 26:24)
“You will see the deliverance the Lord will bring you.” (Exodus 14:13)
“He will never leave you nor forsake you.” (Deuteronomy 31:6)
“It will go well with you.” (2 Kings 25:24)
“You will have success.” (1 Chronicles 22:13)
“He will not fail you or forsake you.” (1 Chronicles 28:20)
“You will not have to fight this battle; see the deliverance the Lord will give you.” (2 Chronicles 20:17)
“When you lie down, your sleep will be sweet.” (Proverbs 3:24)
“He who made you will help you.” (Isaiah 44:2)
“You will not be put to shame; you will not be humiliated.” (Isaiah 54:4)
“I will surely save you out of a distant place.” (Jeremiah 46:27)
“You will be a blessing.” (Zechariah 8:13)
“The pastures in the wilderness are becoming green. The trees are bearing their fruit; the fig tree and the vine yield their riches.” (Joel 2:21-22)
(I love that last one in particular, because it is such a vivid word picture that even when we’ve been in an extended season of “winter”, a new season of life and growth and rebirth is coming! It’s not a “maybe” — it’s a promise!)
These promises are comforting, but know this: A promise is not received until you take it for yourself. God gives these promises to those who put their trust in Him, but you must choose to receive them in faith. And “faith is confidence in what we hope for and assurance about what we do not see.” (Hebrews 11:1)
To recap once again: When we are afraid,
- Rest in the affirmation of God.
- Take Action as He directs it in Scripture.
- Receive His promise to you.
One final observation is that in many of the same verses where we are told, “Do not be afraid,” we are also exhorted: “Do not be discouraged”, or “Do not be fainthearted,” or “Do not panic”, or “Do not be dismayed.”
Again, as our Creator, God knows that fear and discouragement are closely linked. In our doubt, we fear. Closely thereafter, we are so likely to also become discouraged — especially in an extended season of fear and doubt.
So, when you are afraid or when you are discouraged: Examine the root of your fear and look for your doubt. Then, follow the pattern God has established in Scripture. As your doubt in the unknown is replaced by confidence in who God is, your fear will also recede.
Rest in the affirmation of God; take the action as He has directed in Scripture; and receive his promise.
Scripture Analysis – PDF: Do Not Be Afraid
Edited to Add: I want to acknowledge the very real existence of PTSD, Panic and Anxiety Disorder, and other mental health struggles related to fear. I am not ashamed to say that I live with both PTSD and Panic and Anxiety. To have a chemical response in your body overcome your physical ability to remain rational is a terrifying experience. It is not a mind-over-matter situation. This post is in no way intended to suggest that. All that said, as part of an overall positive mental health regimen, meditating on God’s goodness, His faithfulness, and His sovereignty has been extremely helpful to me in my life’s journey.
 There are eighty-one instances of “Do not be afraid” in the NIV translation: https://www.biblegateway.com/quicksearch/?quicksearch=%22Do+not+be+afraid%22&qs_version=NIV&limit=100. For the purpose of my study, I selected 72 of the 81 verses where this phrase appears. The PDF attachment above shows my analysis.
 These are only a few selections. See attachment for the full list of affirmations, directives, and promises.