Good is more laborious than bad. One wrecking ball can destroy a structure it took months to build; one driver can snarl traffic for hours in spite of thousands of good drivers; as Napoleon said to his brother, “Remember, it takes 10 campaigns to create esprit de corps which can be destroyed in an instant.”

That is why we should marvel at the tremendous progress human beings have made. Yes, we have a million problems, and a single terrible war can wipe out centuries of advance (see the first sentence above). Nonetheless, child mortality and extreme poverty have been cut in half in recent years, and humanity’s ethical awareness has made remarkable strides forward.

Everyone acknowledges that we still have very far to go. But it matters to see how far we have come because inaction cannot be excused by “it doesn’t make a difference anyway.” Indeed it does, and we can change the world — are changing the world — step by step. As Napoleon also said, “More battles are lost by loss of hope than by loss of blood.” Don’t lose hope — goodness is a battle worth fighting.

Rabbi David Wolpe is spiritual leader of Sinai Temple in Los Angeles. Follow him on Twitter: @RabbiWolpe. His latest book is “David: The Divided Heart” (Yale University Press).