'Tribulation' in the Bible

and have not root in themselves, but are temporary; afterward tribulation or persecution having come because of the word, immediately they are stumbled.

For those will be days of tribulation, the kind that hasn’t been from the beginning of the world, which God created, until now and never will be again!

But in those days, after that tribulation, the sun shall be darkened, and the moon shall not give her light,