Psalm 119:121-128 imparts lessons about dependence on God's justice, commitment to righteous living, seeking protection from the wicked, desire for divine instruction, renunciation of falsehood, trust in God's Word, patience for His intervention, and plea for His mercy. These lessons inspire believers to persevere in their faith, trust in God's righteousness, and remain steadfast in obedience to His Word despite opposition or adversity.