^7:14 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.

I answered, “Sir, you know.”

John acknowledges that the elder since his death has had access to the knowledge of heaven. John doesn't have this privilege yet.

And he said, “These are they

• who have come out of the great tribulation;

  This is the tribulation, Christ refers to in Matthew 24:21, where 'the then' refers back to Matthew 24:15 when we see the "abomination of desolation standing in the holy place"

  Caution: the Rapture appears to be an absolute dividing line. That is, if you rejected Christ before the rapture, you will be deceived forever. (2 Thessalonians 2:10-12). Others believe you have a chance during the tribulation (2 Peter 3:9-10), however, since this verse comes after verse 9.

  There will be plenty of Bibles, Christian literature, 144,000 sealed Israelites, and, as God wills, this Internet study remaining during the great tribulation.

• they have washed their robes and made them white in the blood of the Lamb.

  The white robes are the "righteous acts of the saints.", Revelation 19:8. That this multitude are redeemed believers cannot be questioned because of the washing of their robes.

  To Sardis, Revelation 3:4, the soiled garments, that is, the unrighteous acts, keep most from walking with Christ. The walking is fellowship, and we can only do that if there is no sin. Sin is cleansed by His blood, 1 John 1:7.

  Isaiah 1:18 refers to this process. Sins are equated to scarlet, yet they will be made white as snow.

There is no doubt about it, though, a multitude of believers come out of the GREAT TRIBULATION period!