Revelation 16:4 Meaning

2And the first went, and poured out his vial upon the earth; and there fell a noisome and grievous sore upon the men which had the mark of the beast, and upon them which worshipped his image.

3And the second angel poured out his vial upon the sea; and it became as the blood of a dead man: and every living soul died in the sea.

4And the third angel poured out his vial upon the rivers and fountains of waters; and they became blood.

5And I heard the angel of the waters say, Thou art righteous, O Lord, which art, and wast, and shalt be, because thou hast judged thus.

6For they have shed the blood of saints and prophets, and thou hast given them blood to drink; for they are worthy.