2 Peter 2:6

and turning the cities of Sodom and Gomorrah into ashes condemned them with an overthrow, having made them an example unto those that should live ungodly;

Sodom and Gomorrah ... These cities were destroyed by God because of their wickedness; and it should not be lost on people of our own generation that the very type of sins prevalent in those two cities has become accepted in some circles today. Such a thing is a commentary upon the depravity of our own era. What were those sins?

The sin of Sodom was unnatural lusts (Genesis 19:5), and pride with fullness of bread, and abundance of idleness, especially among the women, and hard-heartedness towards the poor (Ezekiel 16:46, and Jude 1:1:7).[28]

It is quite significant that the two destructions in view in this and the preceding verses were (1) by water in the first instance, and (2) by fire in the second, a sequence which we have already observed was pointed out by Jesus himself (Luke 17:25ff).

Barnett noted that:

The sequence also prepares for 2 Peter 3:6,7, where the destruction of the world that then existed by water serves to warn that the heavens and the earth that now exist have been stored up for fire.[29]

[28] James Macknight, op. cit., p. 546.

[29] Albert E. Barnett, op. cit., p. 190.