That's an inspiring quote. But it is flawed. It is designed to instill passion and motivation in the listener's heart. But it is missing a virtue which is a strictly necessary ingredient for making an actual positive impact on the world: subtlety.

If you are motivated by addressing humanity's long-term challenges, please do not attempt to bludgeon others into being more thoughtful or compassionate. Instead, learn first how human society works. Learn how to motivate social change in the least destructive way (all change is costly to someone). Learn why people oppose you, and what their interests are, and try to come to a common ground. Don't go off half-cocked. Learn subtlety.

Nobody talks about subtlety. It is an under-appreciated virtue, and one of the most important.