1.  What does it mean? God’s wrath is his ‘resolute action in punishing sin’.  It is the active expression of his hatred toward irreligion and moral evil.  ‘The wrath’ (Rom 2:5; 5:9) may refer to the future ‘day of wrath’, or to ‘present providential events and processes in which divine retribution for sin may be discerned’ (such as the action of the law in stirring up latent sin, Rom 5:20; 7:7-13, and the role of the magistrate in sentencing criminals, Rom 13:4f.)  God’s wrath is the expression of his justice, Rom 3:5

2.  How is it revealed? In Rom 1:18, the tense indicates that it is a constant disclosure (‘is being revealed’); ‘from heaven’ implies a universal disclosure (in contrast to ‘in the gospel’ in the previous verse).  It is a disclosure which imprints itself on every person’s conscience.  Even those whom God has ‘given up’ to do uninhibited evil (Rom 1:28) still know God’s righteous decree and punishment (Rom 1:32).  The gospel prepares us for its good news by telling us of the coming day of God’s wrath and judgment, Rom 2:5.

Furthermore, a pattern of degeneration – from true religion to idolatry to immorality – can be discerned in every generation.  And, for those who have eyes to see, this is but an expression of God’s wrath in ‘a process of judicial hardening and withdrawal of restraints’ (Rom 1:19-31).

3.  How are people delivered from God’s wrath? This is a pressing question, because all are under God’s wrath, Rom 3:9f, 19.  Paul gives a ringing answer: we are delivered by the blood of Christ, Rom 5:9.  We are justified through faith in him.  And the word ‘propitiation’ summarises the process by which God has set aside his own wrath through expiating sin and cancelling guilt, Rom 3:24f.

(Based on Packer, Knowing God)