"Of David: HaShem is my light and my salvation, I will not fear; HaShem is the strength of my life, I will not be afraid" (Tehillim 27:1). The three primal fears of man are loss of intelligence, danger, and death. Despite his many trials and tribulations, King David was deeply tranquil. He perceived that he was never vulnerable because his wisdom, i.e., "my light," his protection, i.e., "my salvation,"and his very life, i.e., "my life," came directly to him from HaShem's kindness. King David's great clarity of HaShem's goodness to him, infused him with dynamic trust in HaShem. His great faith in HaShem effectively worked to master over all of his fears.
King David teaches us how to overcome all three fears by revealing that HaShem oversees our intelligence, protection, and life.
Repeat the verse, "Of David: HaShem is my light and my salvation, I will not fear; HaShem is the strength of my life, I will not be afraid". Strengthen your faith that HaShem actively grants you your intelligence, protection, and very life. Internalize and be inspired by the positive message of King David's insight -- and attain peace of mind.
(Based on the commentary of the RaMad Valli to Tehillim