The faithful in Christ have already cast their lot. It is the unbelievers that need to waken. I think that is why prophesy is used as a tool of the church. If people don't believe that the world will end, they need to be cautioned.
That sounds kind of like scaring them into "belief".
How about Jesus Christ just saving them by his own sovereign grace?
That suggests that people are too dumb to realize that, end of the world or not, THEY ARE GOING TO DIE. Just about everyone who's ever lived has died (exceptions for Enoch, Elijah, and people still alive, but a day older, today :-), but the end of the world has never happened.
To me, the first fact is a much greater motivator. DEATH, folks -- YOURS. There's no avoiding your physical death; aren't you interested in escaping spiritual death? (hypothetical question, not aimed anywhere in particular)