A   ⁴For if God did not spare the angels who sinned, but cast them down to hell and delivered them into chains of darkness, to be reserved for judgment; ⁵ and did not spare the ancient world,

B  but saved Noah, one of eight people, a preacher of righteousness,

A’  bringing in the flood on the world of the ungodly; ⁶ and turning the cities of Sodom and Gomorrah into ashes, condemned them to destruction, making them an example to those who afterward would live ungodly;

B’  ⁷ and delivered righteous Lot, who was oppressed by the filthy conduct of the wicked ⁸ (for that righteous man, dwelling among them, tormented his righteous soul from day to day by seeing and hearing their lawless deeds)—⁹ then the Lord knows how to deliver the godly out of temptations

A’  and to reserve the unjust under punishment for the day of judgment, ¹⁰ and especially those who walk according to the flesh in the lust of uncleanness and despise authority.

A:  Judgment (Sinful Angels, Sinful World).   

B: Deliverance from Judgment (and Temptations).