Revelation 7:14

And I answered him, "Sir, [surely] you know." And he said to me, "These are the people who have come through the terrible persecution, and they have washed their robes and made them white with the blood of the Lamb.

1 John 1:7

But, if we live in the light [of righteousness] just like God [constantly] lives in the light [of righteousness], we can truly share a relationship with one another and [can know that] the blood of Jesus, God's Son, continues to cleanse [our spirits] from all of our sins.

Hebrews 9:14

how much more will the blood of Christ, who through the eternal Holy Spirit [or, His eternal Spirit] offered Himself without [moral] blemish to God, cleanse our consciences from deeds which lead to [spiritual] death to serve the living God?

Revelation 1:5

[It is also] from Jesus Christ, who is the Faithful Witness [to the truth], the Firstborn from the dead [i.e., the first One raised never to die again], the Ruler of the kings of the world. May there be honor and power forever and ever to Christ, who loved us and released us from our sins by His blood [Note: Some manuscripts say "washed us" since the two words are spelled almost alike].

Revelation 22:14

Those who wash their robes are blessed because [then] they will have the right to [eat from] the tree of life, and will [be able to] enter the city through the gates.

Matthew 24:21

There will be great trouble [during these times], such as had never been from the beginning of time up to the present, or ever will be [in the days to come].

John 13:8-14

Peter said to Him, "[No], you will never wash my feet." Jesus replied to him, "If I do not wash you, you will not be able to participate with me [i.e., as a disciple]."

John 16:33

I have said these things to you so that you can have peace in [fellowship with] me. You will have trouble in the world, but cheer up, for I have conquered the world."

Acts 14:22

[Along the way] they strengthened the hearts of the disciples, urging them to continue [to believe and practice] the faith and [explaining] that entering God's [heavenly] kingdom [See II Tim. 4:18] requires enduring many trials.

Romans 5:3

And not only this, but we also rejoice in our troubles, knowing that [experiencing] troubles produces endurance;

1 Corinthians 6:11

And some of you have practiced such things, but you were washed [i.e., from your sins. See Acts 22:16]; you were dedicated [i.e., set apart for God's service]; you were made right with God in the name [i.e., by the authority] of the Lord Jesus Christ, and by the Holy Spirit of our God.

Ephesians 5:26-27

so that He could dedicate her [to Himself], after cleansing her by means of the washing of water [i.e., immersion], accompanied by the word. [Note: "The word" here refers either to a person's profession of faith (See Rom. 10:9) or to the Gospel message (See Rom. 10:17), both of which are associated with immersion].

2 Thessalonians 1:4

Therefore, we ourselves speak proudly about you among the churches of God because of your steadfastness and faith amid all the persecutions and afflictions that you are enduring.

Hebrews 13:12

Therefore, Jesus also suffered outside of the gate [i.e., of Jerusalem] so that He could make people holy through [the shedding of] His own blood.

1 Peter 1:19

but with [the] precious blood of Christ, who represents an unblemished lamb, without defect.

Revelation 2:9

I know [about] your suffering and your poverty (but you are [really] rich), and the slander of those who say they are Jews, though they [really] are not, but are a synagogue of Satan [i.e., they claimed to be an assembly of God's people, but in reality were serving Satan].

Revelation 5:9

And they sang a new song [which went like this]: "You deserve to take the book and break the seals on it, for you were killed and, with your blood, you purchased people for God from every tribe and language and race and nation,

Revelation 6:9-11

And when the Lamb broke open the fifth seal, I saw underneath the altar the souls of those who had been killed for [believing and preaching] God's message, and for the testimony [about Jesus] which they had maintained.

Revelation 12:11

And they [i.e., the brothers. See 6:9-11] gained the victory over Satan by the blood of the Lamb, and by [remaining true to] the message of their testimony. And they did not love their lives [so much that they refused] to die [for their faith].

Revelation 15:2

And I saw what seemed to be an ocean of glass, mixed with fire, and those who had been victorious over the beast, his statue and the number of his name. They were standing beside [or, "on"] the ocean of glass and held harps [given to them] by God.

Revelation 17:6

And I saw that the woman was drunk on the blood of God's holy people and on the blood of those [who were killed] witnessing about Jesus. And when I saw her I was greatly amazed.

Treasury of Scripture Knowledge

Summary

And I said unto him, Sir, thou knowest. And he said to me, These are they which came out of great tribulation, and have washed their robes, and made them white in the blood of the Lamb.

General references

Bible References

And have

Revelation 1:5
[It is also] from Jesus Christ, who is the Faithful Witness [to the truth], the Firstborn from the dead [i.e., the first One raised never to die again], the Ruler of the kings of the world. May there be honor and power forever and ever to Christ, who loved us and released us from our sins by His blood [Note: Some manuscripts say "washed us" since the two words are spelled almost alike].
John 13:8
Peter said to Him, "[No], you will never wash my feet." Jesus replied to him, "If I do not wash you, you will not be able to participate with me [i.e., as a disciple]."
1 Corinthians 6:11
And some of you have practiced such things, but you were washed [i.e., from your sins. See Acts 22:16]; you were dedicated [i.e., set apart for God's service]; you were made right with God in the name [i.e., by the authority] of the Lord Jesus Christ, and by the Holy Spirit of our God.
Ephesians 5:26
so that He could dedicate her [to Himself], after cleansing her by means of the washing of water [i.e., immersion], accompanied by the word. [Note: "The word" here refers either to a person's profession of faith (See Rom. 10:9) or to the Gospel message (See Rom. 10:17), both of which are associated with immersion].
Hebrews 9:14
how much more will the blood of Christ, who through the eternal Holy Spirit [or, His eternal Spirit] offered Himself without [moral] blemish to God, cleanse our consciences from deeds which lead to [spiritual] death to serve the living God?
1 John 1:7
But, if we live in the light [of righteousness] just like God [constantly] lives in the light [of righteousness], we can truly share a relationship with one another and [can know that] the blood of Jesus, God's Son, continues to cleanse [our spirits] from all of our sins.

The blood

Revelation 5:9
And they sang a new song [which went like this]: "You deserve to take the book and break the seals on it, for you were killed and, with your blood, you purchased people for God from every tribe and language and race and nation,
Revelation 12:11
And they [i.e., the brothers. See 6:9-11] gained the victory over Satan by the blood of the Lamb, and by [remaining true to] the message of their testimony. And they did not love their lives [so much that they refused] to die [for their faith].
Hebrews 13:12
Therefore, Jesus also suffered outside of the gate [i.e., of Jerusalem] so that He could make people holy through [the shedding of] His own blood.
1 Peter 1:19
but with [the] precious blood of Christ, who represents an unblemished lamb, without defect.

General references

Matthew 5:4
"Those persons who feel grief [over their sins] are blessed because they will receive comfort [from God when they repent].