These vials are bowls of the judgement of God! Sores, oceans to blood, fresh water to be as the blood of a dead man, people scorched by the sun, darkness around the beasts throne, Euphrates river dries up , and a large earthquake greater than any ever seen before. There were also hailstones weighing 100 pounds each . What else is there to say??? It's devastation like the world has never seen before and though this seems awful. It appears to give man another chance to repent. 16:9 "They were scorched by the fierce heat, and they cursed the name of God who had power over these plagues. They did not repent and give him glory."
It seems that judgement was given for people who saw it and didn't die,to repent, but instead they blasphemed or spoke evil of God! It doesn't matter how bad it gets for some people, they just won't turn to God. Why not receive God today, before all this massive judgement comes? Why not just receive the gift of God's salvation through Jesus? This just proves that it is God's grace that motivates people and saves people.
Ephesians 2:8 For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast.