But the day of the Lord will come as a thief in the night; in the which the heavens shall pass away with a great noise, and the elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up.
Seeing then that all these things shall be dissolved, what manner of persons ought ye to be in all holy conversation and godliness, looking for and hasting unto the coming of the day of God, wherein the heavens being on fire shall be dissolved, and the elements shall melt with fervent heat?
[KJV (1611)]

But the Day of the Lord will come like a thief. On that Day the heavens will disappear with a shrill noise, the heavenly bodies will burn up and be destroyed, and the earth with everything in it will vanish.
Since all these things will be destroyed in this way, what kind of people should you be? Your lives should be holy and dedicated to God, as you wait for the Day of God and do your best to make it come soon -- the Day when the heavens will burn up and be destroyed, and the heavenly bodies will be melted by the heat.
[GNT (1976)]

The Day of the Lord will come like a thief, and then with a roar the sky will vanish, the elements will catch fire and melt away, the earth and all that it contains will be burned up.
Since everything is coming to an end like this, what holy and saintly lives you should be living while you wait for the Day of God to come, and try to hasten its coming: on that Day the sky will dissolve in flames and the elements melt in the heat.
[NJB (1985)]

But the day of the Lord will come like a thief. On that day the heavens will pass away with a dreadful noise, the elements will be consumed by fire, and the earth and all the works done on it will be exposed.
Since everything will be destroyed in this way, what sort of people ought you to be? You must live holy and godly lives, waiting for and hastening the coming day of God. Because of that day, the heavens will be destroyed by fire and the elements will melt away in the flames.
[CEB (2011)]

But the day of the Lord will come like a thief. The heavens will disappear with a roar; the elements will be destroyed by fire, and the earth and everything done in it will be laid bare.
Since everything will be destroyed in this way, what kind of people ought you to be? You ought to live holy and godly lives as you look forward to the day of God and speed its coming. That day will bring about the destruction of the heavens by fire, and the elements will melt in the heat.
[NIV (2011 ed.)]

But the day of the Lord will come like a thief, and then the heavens will pass away with a loud noise, and the elements will be destroyed with fire, and the earth and everything that is done on it will be disclosed.
Since all these things are to be destroyed in this way, what sort of persons ought you to be in leading lives of holiness and godliness, waiting for and hastening the coming of the day of God, because of which the heavens will be set ablaze and destroyed and the elements will melt with fire?
[NRSV (2011 ed.)]