Jesus asks Martha this question after Lazarus has already been dead four days, past the point where any reasonable person would still be hoping for a different outcome. He doesn't ask “do you believe I can still fix this” while there's still practical room for it. He asks after the situation has become, by every visible measure, finished. The question isn't really about whether Jesus can help in ambiguous circumstances. It's about whether Martha, and whoever reads this, will trust him specifically at the point where hope stops making rational sense. And notice the claim itself: “the one who believes in me will live, even though they die.” This doesn't promise the avoidance of death or loss. It reframes what death is capable of, for those who believe. The fear isn't dismissed as unfounded. It's answered with something bigger than the fear accounted for.