"A belief in nothing is past sad."
It would be, wouldn't it? What gives you the idea that I believe in nothing. I believe in many things. Deities are not part of any of those beliefs.
You may mean that it's sad not to believe in some deity. I don't find that sad at all. I am not sad at all. I believe that the scientific explanations of our universe are amazing. I'm always delighted when another puzzle gets solved.
We are extremely fortunate to be living in a time where many age-old questions are being answered.
When the most important thing about your existence that you want people to know about you is that you have no belief in God, to me that's sad as it gets.
"Tell me the one thing that you want me to know about you that can be said in one sentence."
"Umm, well, I guess the most important thing about me that I want you to know is that I cannot believe in God".
The saddest part of all is that it's not something you can change even if you want to. A man cannot make himself believe that which he does not believe.
That is why I never feel anger towards such folks, only saddness. I do oppose the attempt to convert others to share the pain however.