They say "Oh, I have plenty of time to get right with God. I'll just accept Jesus as my savior once I'm old and on my deathbed." That is a big mistake. How many people do you suppose went to school or work this morning and crashed their car, killing themselves? Do you think they believed they'd die today when they left the house?
Anything can happen. A plane can crash through your ceiling right now, a maniac could bust in through your windows and blow your brains out, or you could have some undiagnosed illness you didn't even know about and drop to the floor this instant. Where do you think you'd go if any of these happened? That's why you have to be saved right now. You can't say "Oh I have decades left. I'll do it on my deathbed." You don't know when you'll die. Unexpected things happen each day.