2 Peter 2:5

And He did not spare the original world. It is the same world in which the human race now dwells, which was inhabited by those who lived before the flood. Yet, nonetheless, that original world is rightly called another, as it is written in the …

But He preserved Noah, the preacher of righteousness, etc. It is known to all that Noah was born in the tenth generation from Adam, but he is called the eighth because eight people survived the flood, of whom he was one. He mentions the number …

Not without reason does the apostle begin with believers, who are more honorable, but he wishes to show that they are liable to greater condemnation for their sins. They have the advantage of being the first called to apostleship. Therefore, for going astray from the …

And spared not the old, the antediluvian, world, but he preserved Noah the eighth person - that is, Noah and seven others, a preacher as well as practicer, of righteousness.

And spared not the old world,.... In distinction from the present world, that now is; which was, as it were, formed anew out of that which was destroyed by the deluge.

Contrasted with the densely peopled "world of the ungodly." preacher--not only "righteous" himself (compare 2Pe 2:8), but also "a preacher of righteousness": adduced by Peter against the licentiousness of the false teachers (2Pe 2:2) who have no prospect before them but destruction, even as it overtook the ungodly world in Noah's days.

Spared not the old world - The apostle’s argument is this: If God spared not the rebellious angels, nor the sinful antediluvians, nor the cities of Sodom and Gomorrha, he will not spare those wicked teachers who corrupt the pure doctrines of Christianity. Saved Noah the eighth - Some think that the words should be translated, Noah the eighth preacher of righteousness; but it seems most evident, from 1Pe 3:20, that eight persons are here meant, which were the whole that were saved in the ark, viz. Shem, Ham, Japhet, and their three wives, six; Noah’s wife seven; and Noah himself the eighth. The form of expression, ογδοον Νωε, Noah the eighth, i.e. Noah and seven more, is most common in the Greek language. So in Appian, Bell. Pun., p. 12, Τριτος δε ποτε εν σπηλαιῳ κρυπτομενος ελαθε, sometimes he the third (i.e. he with two others) lay hid in a cave. Andocides, Orat. iv. p. 295: Αἱρεθεις επι τουτῳ δεκατος αυτος, he himself the tenth (i.e. he and nine others) were chosen to this. See a number of other examples in Kypke. World of the ungodly - A whole race without God - without any pure worship or rational religion.