My sentence was:
Ignoring atrocities by both atheists and religious, I don't see evidence that improvements to our world are all the result of atheism, and that religion holds us back.
I assume you don't believe that all improvements to the world are the result of atheism; neither do I.
I occasionally hear someone supporting the view that only atheists can improve human knowledge; this, because the religious are not truly scientific and will, therefore, inject their supernatural and unscientific views. I'm surprised you haven't heard of views such as this, but I don't wish to try to find examples; perhaps I'll start collecting them when I come across them in the future.