David wrote Psalm 3 during a time of great persecution. His confidence in the LORD is very evident in this Psalm. He was able be courageous and strong because He knew the Word and the promises in it.
LORD, I have so many enemies that are against me. They are saying You will not deliver me. I know better than that. You are my shield, my glory, the One who lifts me up. When I call out to You, wonder of all wonders, You answer from Your home on high.
When I rest, You sustain me and keep me safe. Even though it feels like thousands are attacking from every side I will not fear. You will deliver me by giving them a punch in the jaw.
From You comes deliverance and blessings on your people. (My personal transliteration of Psalm 3.)
Blessings to you and yours!