This psalm speaks of the fear- vs. 4- troubles- vs. 6, 17- afflictions - vs. 19- of the righteous. 

This psalm speaks of the LORD delivering and rescuing His people from afflictions- vs. 4, 6, 17, 19. 

Psalm 34 speaks of God protecting HIs people- vs. 7, 9, 10, 15, 20, 22.

This psalm speaks of God judging the wicked- vs. 16, 21.

Psalm 34:20 is applied to Christ's death on the cross- John 19:36 and context.  John 19:36 also applies to Jesus fulfilling the picture of the Passover Lamb in Exodus 12:46; Numbers 9:12. But Jesus also fulfills the picture of the righteous sufferer in the Psalms. 

The above idea stretches the idea of God delivering the righteous. If we do not see it fulfilled in this life, we shall see it in the resurrection.

I Peter 2:3 alludes to Psalm 34:8 and I Peter 3:10-12 quotes Psalm 34:12-16. The righteous people who received this epistle were experiencing troubles, fears, and afflictions. Psalm 34 gives them assurance that ultimately God would deliver the righteous from all of these.