en_tn/1ti/04/02.md

by the hypocrisy of liars

This can be stated as a separate sentence if verse 1 is ended with a period. Alternate translation: "They will learn these things by the hypocrisy of liars" or "They will learn these things from hypocrital liars"

their own consciences having been seared

Possible meanings are 1) Paul is speaking of people who can no longer tell that they are doing wrong as if their minds were ruined. He speaks of their minds being ruined as if their minds were skin that someone had burned with a hot iron. Or 2) Paul is speaking of these people as if Satan had put a mark on them with a hot iron to indicate that they belong to him. (See: rc://en/ta/man/jit/figs-metaphor)

seared

touched with a hot object until it burns brown or black