2 Peter 2:7,8

‘And delivered righteous Lot, sore distressed by the lascivious life of the wicked, (for that righteous man living among them, in seeing and hearing, vexed his righteous soul from day to day with their lawless deeds),'

But one man, Lot, again a ‘righteous man', was distressed by their lasciviousness and was vexed by it continually day by day, was delivered. So in these last two examples, while judgments came on those who lived lasciviously, there were a remnant who were saved. We may feel that Lot did not reveal himself as particularly righteous in the way that he behaved. But the point is that he believed God and in the end obeyed Him, even though somewhat reluctantly.

And the same was now true in a lascivious world, destined for judgment, with the few, the new people of God, being delivered because of their righteousness. The righteousness is comparative. The point is that even in his sins, Lot's heart was turned towards God. For the depiction of both Noah and Lot as ‘righteous' compare the Wisdom of Solomon 10:4, 6 among the apocryphal books.