The first vial, Revelation 16:2 says, produces a great sore (a disease/epidemic) that breaks out amongst the people of the kingdom of the Antichrist. The second and third vials are God's wrath poured out upon the waters (the sea and the rivers), turning them all to blood. Whether or not that is going to be literal – that God is going to turn them to literal blood – I have no idea. Perhaps we cannot know until the very end. But what is for sure is that some judgment of God will affect the water upon the earth – water that heretofore has produced a large amount of food for the anti-Christian kingdom. The text says that everything in the waters dies, causing undoubtingly food shortages in parts of the anti-Christian kingdom. The fourth angel pours out his vial of God's wrath upon the sun, causing it to send out heat waves that scorch men upon the earth in this kingdom.
These are righteous judgments of God poured out upon the wicked kingdom of the Antichrist. Notice the response of the angels and of the souls in glory:
And I heard the angel of the waters say, Thou art righteous, O Lord… (He is responding to these vials being poured out) …which art, and wast, and shalt be, because thou hast judged thus. For they have shed the blood of saints and prophets… (Remember the persecution and the death of the two witnesses) …and thou hast given them blood to drink; for they are worthy. And I heard another out of the altar say, Even so, Lord God Almighty, true and righteous are thy judgments. Revelation 16:5–7, KJV
These are the judgments of God for the kingdom of man that has abused His church. He is not silent, beloved, but He sends His vials. He pours them out and down for their abuse of His beloved Bride. In the anti-Christian kingdom, man lives in sin thinking that there will be no consequences for his sin. Thinking that man has overcome all the effects of the curse of God and His consequences upon sin.
Our scientists, they will say,have cured every disease. We have prevented every natural disaster. We have controlled the world. We may live as we please and not suffer for it.And that lasts, for the anti-Christian kingdom, but a short while. God sends out an outbreak of disease that spreads throughout the Antichrist’s world kingdom. And I imagine, beloved, that it will be tied to the very lust-filled sin that man commits with abandon in his kingdom.These vials are God's judgments. And God's judgment has consequences for the sin that is committed in this kingdom. The cup of iniquity is filled. These are judgements that will bring the proud anti-Christian kingdom to its knees, just like the ten plagues brought the kingdom of Egypt to its knees. Although there are only four vials here poured out upon nature and in Egypt there were ten plagues, there is undoubtedly a connection here between the first four vials and the ten plagues of Egypt. The first four vials are very similar to a number of the plagues that fell upon Egypt (the great sore and the boils; water turning to blood; darkness). Those plagues brought Pharaoh in Egypt to his knees. So too these vials will do the same to the Antichrist and his kingdom.1
Cory Griess
2 So the first angel went and poured out his bowl on the earth, and harmful and painful sores came upon the people who bore the mark of the beast and worshiped its image.