I overheard a bit of a sermon in which the priest said “The moment of our death is the most important moment in our life.”
It is certainly true that it is an important moment, as it is our last. There is so much uncertainty beyond those moments. However, whether you believe in reincarnation, some sort of afterlife, or just simply that the end is the end, if the final moments of your life are the most important, then you have not lived.
If you believe that there is no afterlife, that once you close your eyes that final time there is nothing more, then to say that these moments are your most important is to say you left no legacy. You left nothing behind of importance.
If you believe in the circle of reincarnation, whether it be the cycle of karma, or simply a continuation of existence, then to say that those final moments are your most important is to say that you have done nothing to improve your lot or the lot of others.
If you believe in an afterlife, a heaven or a realm of the dead, then to say that the final moments are the most important is to say that you walk before your god with nothing to show for your life.
On average, humans live about sixty to eighty years. That is so much time that can be spent taking care of your fellow man, or bettering yourself in some way. That is so much time to do good in the world. That is so much time to make a difference even if it is for just one person.
No, as important as those final moments may be, they are not the most important. Whether you believe it to be the end of ends, a short respite before returning to battle, or a gateway to the arms of your god or goddess, it is still but a moment.
When you leave this world, leave it better for your having lived.
When you return to the cosmos, do so having bettered your karma for your next life.
When you enter the arms of your god or goddess, be sure you have something to show them.
Do not, allow your final moments to be the most important ones. That would be a crime against your self, your god, and your people.