What does the Bible say about not fretting over evildoers?

In Psalm 37, believers are reminded to not fret because of evildoers or be envious of the wicked. This exhortation comes from a recognition that the apparent success of the ungodly is fleeting. David, reflecting on his own life experiences as an older man, encourages us to trust in God's justice. He assures us that the wicked will be cut down like the grass. The biblical understanding here is that while we may see the prosperity of those who reject God, it is important for believers to remain steadfast in faith, knowing that God’s ultimate plan will prevail, and evildoers will face His judgment.