What quotes from Paradise Lost describe the wrath and power of God?

In Paradise Lost, God is not as excessively wrathful as he is rational. Compared to the emotional Satan, God is presented as a portrait of reason. When discussing how Adam and Eve will fall to temptation in the future, God does not get wrathful, necessarily, though there is a sense of indignant anger at their failings:

. . . So will fallHee and his faithless Progeny: whose fault?Whose but his own? ingrate, he had of meeAll he could have; I made him just and right,Sufficient to have stood, though free to fall. (book 3, verses 95–99)

God is indignant that the creations blame their creator for their own failings and sins. Milton's God does not so much punish disobedient creations as the creations punish themselves through their own selfish decisions. While God is all-powerful, he cannot control what angels and humans choose to do with their freedom. God's indignant justice is contrasted with the Son's desire to save humanity from themselves.
As for quotes showing God's power, God's introduction proper in book 3 sets up that power and majesty in Milton's description of heaven:

Now had the Almighty Father from above,From the pure Emperyean where he sitsHigh Thron'd above all heighth, bent down his eye,His own works and their works at once to view (book 3, verses 56–59)

That all the realms—heaven, creation, and hell—can be surveyed from God's vantage point showcases God's power over all these realms, even though humans have much dominion over the animals and plants and Satan believes he rules in hell. As long as God can see all of them, they can never hide their intentions from them, and thus they never have the upper hand.