Revelation 8:3,4

Another angel appears with a censor and much incense, and offers it with the prayers of all saints. And the smoke of the incense and the prayers of the saints ascend up before God. This is not the first time we have met the prayers of the saints in this book. In the sixth chapter we heard them pray: "How long, Lord, dost thou not judge and avenge our blood on them that dwell on the earth?" That is upon their persecutors and the persecutors of the church. At the cry of God's people God will avenge. This scene shows that God will hear their prayers, vindicate their cause and overthrow their enemies.