3:10 day of the Lord. Compare I Thessalonians 5:2. The very first phase of “the day of the Lord” will indeed be sudden and unexpected, when the great rapture of all believers, dead and living, into the heavens will take place (I Thessalonians 4:13-17; I Corinthians 15:51-53). Then the day of the Lord will continue for the seven-year period of tribulation judgments on earth (see on Daniel 9:24-27; Matthew 24:15-30; Isaiah 13:9-11) and the thousand-year millennial reign of Christ on earth following that (Revelation 20:6). Because of this thousand-year “day” of the Lord, many expositors, ancient and modern, have interpreted II Peter 3:8 to teach there would be just six thousand years of history before the millennium, thus making a total of seven thousand years to conform to the six work days plus one rest day of creation week. The main Biblical problem with this concept, however, is that it amounts to setting the day for Christ’s return, and would have discouraged any Christians during previous generations from looking for Christ’s return, as He had instructed them to do.
3:10 heavens shall pass away. The “day of the Lord” will be terminated at the end of the millennium with the long-awaited renovation of the old earth by fire. The earth will not be annihilated, any more than it was annihilated at the time of the Flood, but will be completely changed and purified, made new, as it were. All the elements themselves have been under God’s curse (Genesis 3:17-19), so they must be burned up, along with the vast evidences of decay and death now preserved as fossils in the earth’s crust. Possibly this will be a global atomic fission reaction (note the word “dissolved” in II Peter 3:11), or else simply a vast explosive disintegration, involving transformation of the chemical energy of the elements into heat, light and sound energy. What remains after the global fiery disintegration will be other forms of energy, so that, although God’s principle of conservation still holds, the solid earth will seem to have “fled away” (Revelation 20:11).
3:12 hasting unto the coming. That is, “hastening the coming.” From the human perspective, we can hasten the return of Christ by helping to win converts to Him. The reason why He has not already fulfilled “the promise of His coming” (II Peter 3:4) is because He is waiting for all the elect to “come to repentance” (II Peter 3:9).
3:12 heavens being on fire. The “heavens” here probably refer only to the atmospheric heavens, whose elements (hydrogen, oxygen, nitrogen, etc.) must also be “dissolved” (literally “unloosed”), since they are also presently under “the bondage of corruption” (Romans 8:20-22) and must be cleansed and renewed just as the elements of the earth. It is even possible that the purging will dissolve and cleanse the starry heavens also, since these once were the domain of “the angels that sinned” (II Peter 2:4) and since “the whole creation” (Romans 8:22) is now in bondage to the law of decay.
3:12 elements. The word “elements” is translated from the Greek stoicheion, meaning “fundamental constituents” and implies an orderly arrangement of these basic entities. Ever since the primeval curse, which affected even “the dust of the ground” (Genesis 2:7; 3:17), out of which all things had been made, this orderly arrangement has been deteriorating slowly. The disintegration process will be speeded up and completed in the great “dissolving.” This will not be annihilation, however, for God does not “uncreate” what He created. “Whatsoever God doeth, it shall be forever” (Ecclesiastes 3:14). His basic principle of conservation of mass/energy, the most basic and pervasive law known to science, will still hold; Christ will still be “upholding all things by the word of His power” (Hebrews 1:3).