The term describes the “holy ones,” those who believe the gospel of Jesus Christ and so are washed in his blood so as to be righteous, pure in God’s eyes. In the words of the Lord in his letter to Sardis, they “have not soiled their garments” (Revelation 3:4) with the dirt of Babylon’s anti-God mindset. In other words, they refused to help along in building a man-centred paradise, and as a result Babylon in some fashion rejected them so that they died. See also Revelation 17:6.
24 And in her was found the blood of prophets and of saints, and of all who have been slain on earth.”