What I've come to learn is that the world is never saved in grand messianic gestures, but in the simple accumulation of gentle, soft, almost invisible acts of compassion.

This quote is saying that the world won’t be saved by bold, dramatic gestures. Instead, the world will be saved by the effort of many people sacrificing a small amount of their time, energy, and resources to perform acts of kindness. These small compliments, gifts, acts of love, and moments of charity may seem insignificant, but they are essential to making the world a better place. It is the collective kindness of many people that will eventually create a better world.