Therefore the wicked will not stand in the judgment, nor sinners in the congregation of the righteous; (ESV)
The wicked were described as chaff in the previous verse. They have lives of no substance. They are blown about like something that has no worth. Because they are not like the tree planted by God they have no strength and get blown from one disastrous place to another. This imagery very aptly depicts the wicked of any age.
Today, we see people who are just like what the Psalmist has described. Their life is a pursuing of vain pleasures that do not satisfy. They have no place for God in their life and wonder why they are filled with a deep sense of emptiness. The pursuit of vain things is typical of a life of wickedness. The Apostle John wrote of this worldly philosophy and it's futility in 1 John 2:16-17:
1 John 2:16–17
 For all that is in the world—the desires of the flesh and the desires of the eyes and pride of life—is not from the Father but is from the world.  And the world is passing away along with its desires, but whoever does the will of God abides forever. (ESV)
This sheds further light for us. The wicked are chasing after worldly things. And those worldly things are passing away. They are temporal. Those who follow after worldly things will perish just like the world itself will perish. Only the righteous who have set their eyes on things that are eternal will have eternal life.
Have compassion on those who are described as wicked. They are chasing for pleasure but will only find disappointment, and ultimately; judgment. Guide them to Jesus, who gives eternal life.