The answer to this question is revealed in the first three chapters of the Book of Revelation. 

The church at Laodicea is the last church mentioned in Revelation chapter 3. It was an actual church, but it was also prophetically representative of many of the churches now present upon the earth. 

The church prior to Laodicea being mentioned was Philadelphia and prophetically it represents the remnant that will be raptured. The Lord has no rebuke for this church only commendation. Revelation 3:10 the Lord says to the church at Philadelphia: Because you have kept My command to persevere, I also will keep you from the hour of trial which shall come upon the whole world, to test those who dwell on the earth.  

Compare that to the church at Laodicea where the Lord says: Revelation 3:14-18: “And to the angel of the church of the Laodiceans write,

‘These things says the Amen, the Faithful and True Witness, the Beginning of the creation of God: “I know your works, that you are neither cold nor hot. I could wish you were cold or hot. So then, because you are lukewarm, and neither cold nor hot, I will vomit you out of My mouth. Because you say, ‘I am rich, have become wealthy, and have need of nothing’—and do not know that you are wretched, miserable, poor, blind, and naked— I counsel you to buy from Me gold refined in the fire, that you may be rich; and white garments, that you may be clothed, that the shame of your nakedness may not be revealed; and anoint your eyes with eye salve, that you may see.  

Revelation 3:19-22: As many as I love, I rebuke and chasten. Therefore be zealous and repent. Behold, I stand at the door and knock. If anyone hears My voice and opens the door, I will come in to him and dine with him, and he with Me. To him who overcomes I will grant to sit with Me on My throne, as I also overcame and sat down with My Father on His throne. “He who has an ear, let him hear what the Spirit says to the churches.”  

You can see the sharp contrast between the two churches. Focus in on verse 18 where the Lord says they should buy white garments. This is a church filled with lost people. Isaiah 61:10 says: I will greatly rejoice in the Lord, My soul shall be joyful in my God; For He has clothed me with the garments of salvation, He has covered me with the robe of righteousness. The church at Laodicea, the people who make it up are not clothed with a robe of righteousness. They are “naked.” 

Then we come to the verse Revelation 3:20 that many of us have memorized. Notice that Jesus is knocking on the door of this church. Jesus is not in the church He is outside knocking on the door wanting to come in. This is a church that thinks that they have everything, but instead the Lord reveals their real condition they are: wretched, miserable, poor, blind, and naked. 

Revelation 3:22 is the last mention of churches in Revelation for many chapters. Why? Because the rapture occurs and born again believers are no longer on this earth. Those who have actually been born again birthed into the Kingdom of God by the Holy Spirt represented by the church at Philadelphia will be raptured. Those who only profess their faith but have not actually received Christ as their Savior will be left behind. 

I believe Billy Graham was right when he said that 60 to 80% of church members are lost. I think he said that because of so many church members being saved in his crusades. Are you saved? Have you been born again birthed into the Kingdom of God? If you are not sure prayerfully read through 1 John and God will reveal your condition. You can know whether you are saved or not. 1 John 5:13, These things I have written to you who believe in the name of the Son of God, that you may know that you have eternal life, and that you may continue to believe in the name of the Son of God.