Paul said time is short and soon you will give God an account for what you did with your time. Our culture says time is short so take care of yourself. Paul said our time is short, so it's all the more important that we love one another. It's crucial that we live unselfishly and share what we have. It's essential that we not throw away the few hours God has given us on uselessness.
Life is fragile.
Any moment any one of us might suddenly be meeting God face to face, and now is the only time you have to prepare for it. You can't guarantee you'll have another opportunity later. This is good advice. On the other hand, such apocalyptic urgency whether secular or Christian, can be dangerously shortsighted. I counseled a student when I was a Baptist Student Union director who was extremely anxious.