"But the day of the Lord will come like a thief, in which the heavens will pass away with a roar and the elements will be destroyed with intense heat, and the earth and its works will be burned up." (2 Peter 3:10)
Most people are so focused on the mundane, temporal, day-to-day issues of life that they don't see the bigger picture. Someday, and maybe soon, the Lord Jesus Christ will return. This time He will not come as the little helpless baby Jesus, but as the eternal God in all His glory, the King of kings and Lord of lords (see Revelation 19:11-16). The day of the Lord is coming and yet most people are preoccupied with the things of this world that are passing away. It is like rearranging the deck chairs on the infamous Titanic while the ship is sinking!
Those unbelievers who love this present world and reject the prophecies of Scripture, are ignorant regarding coming judgment. But this should not be true for Christians; "Do not love the world nor the things in the world. If anyone loves the world, the love of the Father is not in him." (1 John 2:15)
This does not mean that Christians are to be totally disengaged from this present world, insulated from all unbelievers and just waiting for the Lord to return. Quite the opposite. In this world we are to be ambassadors for Christ, making Him known and proclaiming His Gospel in both our words and deeds. Christians are to be engaged in this world as salt and light. But if we simply blend into the world (love the world), our witness for Christ becomes impotent; "You are the salt of the earth; but if the salt has become tasteless, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled under foot by men." (Matthew 5:13)
Those without Christ have been lulled into a false sense of security, not believing that the Lord will someday return in judgment; "...Where is the promise of His coming? For ever since the fathers fell asleep, all continues just as it was from the beginning of creation." (2 Peter 2:4) They have determined that since Jesus Christ hasn't come back in almost two thousand years, He isn't coming. This is not only faulty logic, but bad theology. Like a thief in the night (unexpected), He will be returning "and the earth and its works will be burned up."
How very foolish then to devote so much of our time, our resources, our lives to that which is only temporal and passing away. Rather, let's focus on those things that are eternal in faith and obedience to Him; Since all these things are to be destroyed in this way, what sort of people ought you to be in holy conduct and godliness, looking for and hastening the coming of the day of God..." (2 Peter 3:11,12). Maranatha!