They need to meditate on the Trinity of 'God the Holy One, the Punisher of Evil and Avenging Judge.'
Rom 1:18 For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who by their unrighteousness suppress the truth.
Zeph 2:3 Seek the Lord, all you humble of the land, who do his just commands; seek righteousness; seek humility; perhaps you may be hidden on the day of the anger of the Lord.