Treasury of Scripture Knowledge
And they cried with a loud voice, saying, How long, O Lord, holy and true, dost thou not judge and avenge our blood on them that dwell on the earth?
So, will God not grant justice to His elect [i.e., His people] who call out to Him [i.e., in prayer] day and night? Will He be slow in helping them?
and to Jesus, the Mediator of a New Agreement [between God and mankind], and to the sprinkled blood [of Jesus], which says better things [to us] than [the blood of] Abel did. [Note: The contrast seems to be that "Abel's blood called for vengeance and death (See Gen. 4:10) whereas the blood of Christ provides mercy and life"].
"And write [this] to the angel of the church at Philadelphia: These are the words of Him who is holy and true, [and] who possesses the key [i.e., the power and authority] of King David, [and] who opens [a door] which no one will close, and who closes one that no one will open:
And they were singing the song of Moses, the servant of God, and the song of the Lamb. [The words were], "Your deeds are great and marvelous, O Lord, God Almighty; your ways are just and true, O King of the nations [or, "ages"].
And the nations were enraged, but your wrath has come [anyway]. The time has come for the dead to be judged and for your servants the prophets to receive their reward, [along with] the saints and [both] the insignificant and important ones who revere your name. [It is also time] to destroy those who destroy the earth."
Then I heard the angel [in charge] of the waters saying, "You are just, [you] who are [in the present] and who were [in the past], O Holy One, because you have judged [that these things should happen].
Be glad, heaven, and you saints, and you apostles, and you prophets, for God has brought judgment on her for you [i.e., for the way she treated you].'"
For His judgments are true and just; He has judged [i.e., condemned] the great prostitute who corrupted the earth with her sexual immorality, and He has punished her for [shedding] the blood of His servants."
For these are times for punishment [i.e., to be inflicted on Jerusalem], so that everything written [i.e., by the prophets] may be fulfilled [i.e., about Jerusalem's destruction. See Dan. 9:26-27].
Do not take revenge on someone who has wronged you, but leave it up to God's wrath [to take care of it], for it is written [Deut. 22:35], "The Lord says, I will pay people back [for doing wrong] because taking revenge belongs to me."
2 Thessalonians 1:6
For it is a just thing for God to repay with affliction those people who are troubling you,