“Let us rejoice and be glad and give him glory!  For the wedding of the Lamb has come, and his bride has made herself ready.  Fine linen, bright and clean, was given her to wear.  (Fine linen stands for the righteous acts of the saints.)” (Rev 19:7-8).

“Then one of the elders asked me, ‘These in white robes - who are they, and where did they come from?’ I answered, ‘Sir, you know.’  And he said, ‘These are they who have come out of the great tribulation; they have washed their robes and made them white in the blood of the Lamb’ ” (Rev 7:13-14). 

Where does this multitude get their white robes to wear?

The pre and mid-Tribulation theories state that Revelation 7:13-14 must be talking about Christians who got left behind in the rapture because they were not good enough to be taken at that time.  Realizing the error of their ways, these “fallen Christians” repented, got their act together, and had to suffer persecution and God’s wrath poured out on the earth. 

Although pre and mid-Tribulation theorists state that the Church is not specifically mentioned in the book of Revelation during the Tribulation, it is evident that large numbers of Christians are present to the very end.  All through the ages, where Christians are present, the Church is present. 

A Matter of Emphasis.

The Church is mentioned in Revelation, but it is not emphasized because it is no longer center stage.  God and the nation of Israel were the emphasis of the Old Testament age, and Jesus Christ and the Church were the emphasis of the New Testament age.  In chapters two and three of Revelation, Jesus speaks to the Church to prepare believers for what is to come, then the emphasis is on the seven years of Great Tribulation -  the age of Satan and the world.