Commentaries:
The ungodly are sinners. God, being the just God that He is, judged according to His law. He wanted to save these people so that they could be resurrected and given an opportunity for salvation at a better time. Not being able to abide their rebellion, He wiped them out because they were sinners, ungodly, breaking His law.
John W. Ritenbaugh
The Covenants, Grace, and Law (Part Sixteen)
Other Forerunner Commentary entries containing 2 Peter 2:5:
Genesis 6:5-13
Genesis 6:7-9
Galatians 1:6
Hebrews 11:4-7
Hebrews 11:7
1 Peter 3:18-20