The Lord isn’t slow to keep his promise, not slow in the way some people understand it. Instead, he’s being patient with you. He doesn’t want anyone to be destroyed. He wants everyone to turn away from their sins.
They spoke curses against the God of heaven because of their pains and their sores. But they still refused to turn away from the sins they were committing.
They were burned by the blazing heat, and they spoke curses against the name of God, who had power over these plagues. But they refused to turn away from their sins and admit that God was right.
Remember that while our Lord is waiting patiently to return, people are being saved. Our dear brother Paul also wrote to you about this with the wisdom that God gave him.
These were the spirits of those who had disobeyed long before, when God was being patient while Noah built the ark. Only a few people, eight in all, were saved from the flood in the ark.