"When He opened the fifth seal, I saw under the altar the souls of those who had been slain for the word of God and for the testimony which they held. And they cried with a loud voice, saying, 'How long, O Lord, holy and true, until You judge and avenge our blood on those who dwell on the earth?' Then a white robe was given to each of them; and it was said to them that they should rest a little while longer, until both the number of their fellow servants and their brethren, who would be killed as they were, was completed." (Revelation 6:9-11)
How long, O Lord? That is the question asked by the martyrs. They are pleading for the day of vengeance. Truly, when Jesus comes in glory, it will be to "judge and avenge"—to bring the final and eternal retribution upon those who hate Christ and His followers.
The thought of a day of judgment sends chills down the spines of the great multitude of unbelievers, for "they know God's righteous decree that those who practice such things [sins] deserve to die." (Romans 1:32 ESV) Why else would the wicked go to such extremes, including murder, to silence the voice of Christians? It isn't just our words; our very existence is a proclamation of judgment. We are a living testimony to Jesus' words: "He who believes and is baptized will be saved; but he who does not believe will be condemned." (Mark 16:16)
For centuries, the blood of the martyrs has been crying out, "How long, O Lord?" It began with Abel, the first martyr. God said to Cain, "The voice of your brother's blood cries out to Me from the ground." (Genesis 4:10) Our hymn puts it this way: "Abel's blood for vengeance pleadeth to the skies" (The Lutheran Hymnal 158:4).
Should we be crying "loudly" for vengeance? Our Gospel outreach demonstrates that we don't want anyone to go to hell. Neither does God. "The Lord is . . . not willing that any should perish but that all should come to repentance." (2 Peter 3:9) That's why God went to the ultimate extreme to save us: He punished His own Son for what we have done. That's why missionaries have put their lives on the line in order to bring this truth to the nations. There is forgiveness for all, but not all know this. Thanks be to God for revealing it to us.
Judgment Day is the final affirmation of His words (Mark 16:16). The condemnation of the unbelievers is the validation of the faith of the saints. It is the assurance to the martyrs, "You did not die for nothing." It is the assurance to us all, "As you have believed, so it shall be. Enter into the joy of your Lord." The cry for the day of retribution is a cry for the day of salvation, also. If the former does not happen, neither will the latter.
However, the End is not yet. Therefore, the martyrs and we are told to rest for a while, because "the number of their fellow servants and their brethren" had not yet been completed. So we all wait, clothed with the righteousness of Christ. Then, when the last of the elect enters the family of God, the End will come. When it happens, "look up and lift up your heads, because your redemption draws near." (Luke 21:28) In the meantime, may God give us the zeal and strength to do our part in filling up the number of the elect. By such holiness and godliness, we will be "hastening the coming of the day of God." (2 Peter 3:12)
The condemnation of the unbelievers is the validation of the faith of the saints. It is the assurance to the martyrs, "You did not die for nothing."