How do we know there’s a hell?
We know of hell because the Scriptures speak of it. The Old Testament speaks of hell.
(Psalm 9:17…) “The wicked shall be turned into hell, and all the nations that forget God.”
In the New Testament Jesus speaks of hell in several places. (Mark 9:45,46 )“And if thy foot offend thee, cut it off: it is better for thee to enter halt into life, than having two feet to be cast into hell, into the fire that never shall be quenched: Where their worm dieth not, and the fire is not quenched.”
For more passages, type “hell in Scripture” in your search engine.
Fr. Vincent Serpa, O.P.