"When I am afraid, I will put my trust in You.  In God, whose word I praise, In God I have put my trust; I shall not be afraid.  What can mere man do to me?"  (Psalm 56:3-4)

"Trust and confidence in the Lord is the best antidote against fears" -- John Gill (1697-1771) (Ref. 1, Ref. 2).

     Consider.  On a scale from 1 to 10, with 10 being the highest, how would you rate yourself for trusting in God when you are afraid?

     David wrote Psalm 56 during one of the lowest points in his life.  Saul, the king of Israel, was determined to kill David (1 Samuel 20:30-33).  Even though Jonathan, Saul's son, and David were close friends, Jonathan advised David to flee from Saul (1 Samuel 20:41-42).  David came to Nob to Ahimelech, the priest (1 Samuel 21:1).  David lied to Ahimelech about the purpose of his visit (1 Samuel 21:2).  David received from Ahimelech consecrated bread and the sword of Goliath (1 Samuel 21:6, 1 Samuel 21:9).  David arose and "fled that day from Saul" to Achish king of Gath, a city in Philistine territory (1 Samuel 21:10, Ref. 3). 

Gath was the home town of Goliath (1 Samuel 17:4).  David had killed Goliath in battle (1 Samuel 17:41-49).  David now had the sword of Goliath with him.  The servants of Achish knew of David's reputation.  "Is this not David the king of the land?  Did they not sing of this one as they danced, saying, 'Saul has slain his thousands, And David his ten thousands'?" (1 Samuel 21:11).  The scripture says "David took these words to heart and greatly feared Achish king of Gath" (1 Samuel 21:12).  David then "disguised his sanity before them, and acted insanely" (1 Samuel 21:13).

     Despite David's fear and troubled emotional state, David makes an astounding declaration about trusting in God when he was afraid.  "When I am afraid, I will put my trust in You.  In God, whose word I praise, In God I have put my trust; I shall not be afraid.  What can mere man do to me?" (Psalm 56:3-4).  David repeats his declaration of trust in Psalm 56:11, "In God I have put my trust, I shall not be afraid."  Note the subtle change in tense from "I will put my trust" in verse 3 to "I have put my trust" in verse 11.

In the Hebrew, the word for "trust" means to be boldly confident, secure, and sure (Strong's Exhaustive Concordance - Ref. 4).  When we trust in God, we are boldly confident, secure, and sure in him. 
 
David frequently wrote in the Psalms about trusting in God.  For additional encouragement and strength on this topic, I suggest you read "29 Bible Verses About Trusting God" (Ref. 5).  

David recognized that the remedy -- the antidote -- for fear is to trust in God.  David put his confidence in God and in God's care.  Will you do the same?

A related, closing verse for your consideration:
"Do not fear, for I am with you;
Do not be afraid, for I am your God.
I will strengthen you, I will also help you,
I will also uphold you with My righteous right hand." 
(Isaiah 41:10)

     Apply.  If you are fearful or afraid today, pray to God.  Put your complete trust in God and the promises in his word (Psalm 56:3-4).  God will strengthen you and help you (Isaiah 41:10).  Thank God for his work in you to deliver you from your fear and for taking care of your concerns. 

     Suggested Listening.  Listen to Alan Jackson's Official Music Video, "'Tis So Sweet to Trust in Jesus (Live)."

Related Lessons and Resources
"29 Bible Verses About Trusting God" - Psalm 56:3
"The Remedy for a Troubled Heart (John 14:1)"
"'Fear Nots' of the Old Testament" - Isaiah 41:10

References
1.  https://biblehub.com/commentaries/gill/psalms/56.htm
2.  https://en.wikipedia.org/wiki/John_Gill_(theologian)
3.  https://biblehub.com/hebrew/1661.htm
4.  https://biblehub.com/hebrew/982.htm
5.  https://www.ScriptureWay.com/29-bible-verses-about-trusting-god