We as humans, unfortunately, tend to have a very short-term outlook on ourselves, our lives, as well as our place in the world. We tend not to care about things like where our legacy will lead--several millions or billions of years into the future!!
But here's what I say to that: if everyone looked at their existence in such a way, then from the drug-addled pauper that lives as a street urchin, peddling for pennies at street corners, all the way up to the greatest business tycoons and billionaires of our age, would all strive to improve their lot in life to the absolute maximum extent possible. We would not be satisfied with our weakness, or with the brokenness of the world that surrounds us. We would all seek more.
Because, in truth, we all want to be remembered. In fact, it is to be remembered for all of eternity that is, if not the pinnacle of the things for which we strive as humans, close to the pinnacle of everything that we seek to attain. Instant gratification of the food we eat, the drugs we take, the sex in which we partake, etc... Would all fall away to the more important things. You would realize, in no uncertain terms, that your example is the bedrock of all of your future progeny; they will look to you for guidance, in some way, shape, or form.
Then, I want you to think of this: in the grandest scales of transgression of events, there is only one thing that we remember. It's not the silly, unimportant factoids such as the number of bumps on a basketball, or the score of a single baseball game in a single year of a single era of human history. It's not even the epochs of our history. Because, in truth, our world is only occupying a very small sliver of the vastness of space--and time, and will likely fade away at some point.
No. The only things we remember, in the grandest scales of events, is how something made us feel. It is the emotion of the matter. And the greatest of these emotions, is love. Love is truth, is belief, is God.
If you live in truth, in love, then your legacy will live on forever, for it is the only thing that matters.