Left Behind is a post-apocalypic film franchise about what happens when all of the devout believers worthy enough to make it past the pearly gates get zapped up to Heaven during the rapture and the lowly heathens who don't have Jesus in their hearts are left to toil in this realm of existence. The original franchise stars the very devout, very vocal, former Growing Pains star, Kirk Cameron, which would probably explain why you've never heard of Left Behind.