As an example of the blood people have shed, we may think of Jesus’ words to the Pharisees concerning their being guilty of “the blood of righteous Abel to the blood of Zechariah the son of Barachiah, whom you murdered” (Matthew 23:35; see also Matthew 21:33–46). In relation to the New Testament church, we may think of the martyrdom of Stephen (Acts 7:54–60) and Antipas (Revelation 2:13), and we may include all the saints murdered over the centuries whose souls are under the altar (Revelation 6:9). More specifically, the reference is to the murders triggered by the beast upon those who refused to worship its image, Revelation 13:15. As he had promised, the Lord would definitely vindicate his own (Deuteronomy 32:35, Deuteronomy 32:41, Deuteronomy 32:43; see further Psalm 79:10; Psalm 94:1).
6 For they have shed the blood of saints and prophets, and you have given them blood to drink. It is what they deserve!”