Believe in God and his promises
Psalm 20 was to be read and sung before the war or trial, and David was wise to claim God's blessings, power, and victory before fighting the battle. Let us also remember that as long as there are armies and weapons, nations have boasted about their strength, but such power does not endure or last. Empires and kingdoms have risen to tremendous strength just to fall in the dust throughout history. David, on the other hand, understood that his nation's true strength rested not in arms or weaponry, but in worship, not in firepower, but in God's power, since only God can defend a nation or a person. Then Psalm 20 applies to you in the same way as it applied to David and God's people. Believe in God and his promises!
Faith enables us to have a closer relationship with God. God has no problems about putting his trust in us. But, trusting God might be tough at times. We begin to drift along with the things of the world, relying on power, status, and reputation. The psalmist, on the other hand, makes it clear who we should trust and relying upon. "Many people seem to trust in chariots, whereas others believe in horses, but we always believe in the Lord mighty." (Psalm 20:7). We will never be intimate with someone until we cannot trust. God wants us to put our faith in him completely. He will never leave those who put their trust in Him and seek Him out (Psalm 9:10) We must trust God's faithfulness even when He allows trials. Except God we get nothing ever permanent, concrete, or stable in this world.