Unwanted children are more likely to grown up as felons.

So? Why not just wait and see, then kill them iff they become felons.

Currently we wait and see, and put the felons in prison for life. Very expensive. If you're truly an atheist, you couldn't consider human life sacred. Certainly not someone else's life.

Why in the world would you think this??

The USA only stopped having slaves about 150 years ago. It's been only about 50 years that they were starting to give all citizens equal rights. The sanctity of human life is religion based. Since I'm not religious, I don't see human life as precious. Have no qualms about abortion.

The recent trend toward treating other people's lives as sacred and other people as worthy of humane treatment is the product of social and cultural evolution, not religion. Religion was there during the slavery and racism/sexism you mention and it was there during the Crusades and the Inquisition and all of the other horrors that mankind has brought upon itself. Religion isn't new; the trend you described is new, and it's not due to religion. In fact, there is nothing in the history of this entire world that has made people value human life less than religion has made religious people devalue the lives of those who don't share their faith. History makes this abundantly clear.

But anyway, you're not religious so you don't see human life as precious, and that's fine, but what you said initially was "If you're truly an atheist, you couldn't consider human life sacred. Certainly not someone else's life."

Several hundred million Buddhists and plenty of non-religious atheists would strongly disagree with this assertion.

Secular humanism - Wikipedia, the free encyclopedia

As evident by rape and murder being far more common among atheists and especially in atheistic countries such as France amirite?

emo kid is emo

I agree with this right here.

Wouldn't you think someone who doesn't believe there is something "after" put a little more value on life? Once you're gone, that's it. If you think there's an afterlife, it doesn't really matter because you won't ever "die" anyway.