New Defender's Study Bible Notes
3:7 which are now. The heavens and the earth which “were of old” (II Peter 3:5) were destroyed by water. “The heavens and earth which are now” will be destroyed by fire (II Peter 3:10). Finally “new heavens and a new earth” (II Peter 3:13) will last forever. In the interim of the present cosmos, processes indeed are under the domain of conservation, or even uniformity (note Genesis 8:22).
3:8 thousand years. This verse has been widely misinterpreted as supporting the day/age theory of creation in Genesis 1. In context, however, it has nothing to do with creation week, but rather with the last-days conflict between evolutionary uniformitarianism and Biblical-creationist catastrophism (II Peter 3:3-6). In effect, Peter is not saying that one day means a thousand years but rather than “one day is with the Lord like a thousand years.” That is, God’s judgment on a wicked world will do as much geological work in one day as could be accomplished by uniform natural processes in a thousand years. It is even intriguing (though probably meaningless) to note that two billion years (which is about the current geological estimate for the time required to deposit the earth’s sedimentary rocks, would correspond roughly to six thousand years of Biblical history (during which the earth’s sediments have actually been laid down, most of them at the time of the Flood) if those years each represented 365,000 years (at one thousand years per day).
3:9 slack concerning his promise. The Lord has not forgotten His promise to return to earth, as the scoffers have charged (II Peter 3:3,4), but is still waiting for others to “come to repentance”—that is, to “change their minds,” turning away from conformity to this world’s philosophy (Romans 12:2) and turning to Christ for salvation. But God’s promise will, indeed, be fulfilled (II Peter 3:13).