I leave it up to everyone to interpret it, but my personal interpretation is that there probably ain't no thing such as gods, but there also ain't no such things as "justice", "mercy", "duty", "good", or "evil".
Yet I choose to believe that some acts are better than other.
I believe that helping someone achieve their goals is usually better than hurting them.
Why? Is there a "scientific fact" that makes it true? No, there isn't. Science doesn't care if earth is full of life or if it's a glassed sphere in an infinite void. Both "work" just fine for science.
So my "choice" to prefer one of those is arbitrary (scientifically speaking).
Now why is my believe in that "big lie" any more sane than other peoples believe in the "small lies"?
My belief can't be scientifically falsified (or proven).
And their belief in a benevolent sky daddy also can't be falsified or proven.