"Nevertheless we, according to his promise, look for new heavens and a new earth, wherein dwelleth righteousness." (2 Peter 3:13)
The cosmos consists of "all things"--every system, every structure, every organism, every process, everything--in heaven and in earth. Cosmology is the system and study of the whole cosmos. In his final epistle, the apostle Peter outlines four different cosmologies. One is false, the other three are each true, but at different times in history.
The false cosmology is that of evolutionary uniformitarianism, the doctrine taught by latter-day intellectuals who will scoff: "Where is the promise of his coming? . . . all things continue as they were from the beginning of creation" (2 Peter 3:4). But this is altogether wrong! The first cosmos--the heavens and the earth which were "of old . . . the world that then was, being overflowed with water, perished" (2 Peter 3:5-6). The primeval cosmos, in which "every thing that he had made . . . was very good" (Genesis 1:31), was destroyed in the waters of the great Flood.
The present cosmos, "the heavens and the earth, which are now . . . reserved unto fire against the day of judgment and perdition of ungodly men" (2 Peter 3:7). This "present evil world" (Galatians 1:4) was to last many a long year, but "the day of the Lord will come . . . in the which the heavens shall pass away with a great noise . . . the earth also and the works that are therein shall be burned up" (2 Peter 3:10).
But then, out of the ashes of the old corrupt world, so to speak, God will make a new and incorruptible world. "We, according to his promise, look for new heavens and a new earth, wherein dwelleth righteousness" (2 Peter 3:13).
That cosmos will continue forever! "The new heavens and the new earth, which I will make, shall remain before me, saith the LORD" (Isaiah 66:22). HMM