Question:

I have a fear of dying that expresses itself in a weird way. I’ve read stories of people doing one mitzvah and then dropping dead, because that one good deed was their life’s mission. So now every time I do something good, I think maybe this is my last. Should I try not to fulfill my mission so I can live, or do good deeds and die?

Answer:

There are two types of workers: employees and contractors. A contractor is there to do their job, and that's it. As long as I have completed the tasks given to me, as long as the items on my to-do list are accounted for, I’ve done my bit and I can go home.

But an employee has to work until the day is over. It is not enough that my immediate tasks are complete, I have to seek out more work and ensure every moment of the day is productive. Otherwise I am short-changing my employer.

We live in G‑d's giant factory, and we are all workers, each with a specific role to play. We each contribute our part to the grand scheme of creating a better world. And we have a choice. We can either suffice with fulfilling our obligation alone, and no more, or we can go beyond that. As long as the job is not yet done, as long as the world is not yet full of goodness, we still have work to do.

If you choose to work like a contractor, only looking to fulfill your mission, once your job is done you have nothing more to offer, it is time for you to leave this world. But if you choose to be an employee, to serve G‑d not for your own self-fulfillment but for His sake, then there is no end to the good you can do. And so even once you have fulfilled your personal mission, you go on to another task, and then another, until your day is up.

Never say you've done enough. And don't be scared of running out of good deeds to do. There's still plenty of work out there. Go do it.

There are rare cases when a soul is sent down here with one single mission to achieve, and once that is done, they are free to go back to heaven. Sad for us, these special souls leave us early, and we should be thankful for ever having met them.

Source:

Letter of the Rambam