This is the generic answer from these individuals.
I carry a pocket New Testament on me at all times. I'd show anyone who makes that statement Jude 7.
Jude 1:7 [The wicked are sentenced to suffer] just as Sodom and Gomorrah and the adjacent towns--which likewise gave themselves over to impurity and indulged in unnatural vice and sensual perversity--are laid out [in plain sight] as an exhibit of perpetual punishment [to warn] of everlasting fire. (Amplified)
Yup. That's an excellent, unambiguable passage.