First: materialism/physicalism can contribute to becoming atheist, but they are not assumed by atheism. It's entirely possible to be an idealist atheist.Lately I've been studying viewpoints of various atheists, and am disturbed at many of their radical agendas for society. They want to abolish religions, including home school and religious schools. Basically, they consider non-atheists as people not deserving of participation in society, because of viewpoints so obviously incorrect and untrue.
But considering that atheism merely assumes materialism and physicalism, explaining everything in terms of these, their hatred of spiritual beliefs seems unwarranted.
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.
Second: it's not atheism that will save us, but compassion.