The sixth chapter of Revelation opens with John seeing four seals being opening which releases the so-called “four horsemen of the apocalypse” (Rev. 6:1-8). Then John sees the fifth seal opened,
Revelation 6:9-11 When the Lamb broke the fifth seal, I saw underneath the altar the souls of those who had been slain because of the word of God, and because of the testimony which they had maintained; 10 and they cried out with a loud voice, saying, “How long, O Lord, holy and true, will You refrain from judging and avenging our blood on those who dwell on the earth?” 11 And there was given to each of them a white robe; and they were told that they should rest for a little while longer, until the number of their fellow servants and their brethren who were to be killed even as they had been, would be completed also
The “souls” under the altar are in the heavenly temple. They had sacrificed their blood for the testimony of Jesus Christ. Their blood had been poured out at the sacrificial altar. They live in the presence of God, dressed in their white robes. They have moved from earth, with all its hardships and heartaches, to a reality where they are engulfed in the worship, adoration, praise, and joy of God.
The martyred saints recognize both the holiness and justice of God. They appeal to both aspects as they lament the injustice upon the earth. As John Mark Hicks noted:
The saints before the throne share the lament of those who still live upon the earth. . . . The martyred saints share our lament and continue it in the presence of God. They, too, yearn for the fullness of God’s kingdom to manifest itself in a new heaven and new earth. (“Waiting With Us,” JohnMarkHicks.com)
“Wait” is the divine response. Waiting is what the martyrs must do. Waiting is what the saints on earth must all do, “And not only this, but also we ourselves, having the first fruits of the Spirit, even we ourselves groan within ourselves, waiting eagerly for our adoption as sons, the redemption of our body” (Romans 8:23).
What are we waiting for? The answer from Revelation is that there is more “witnessing” to do (Rev. 6:11; 12:11). God desires more people to come under His rule before Judgment comes.