Some religious people suggest you can't have morality without God, and therefore atheists have no reason to act morally. Some atheists respond by saying we shouldn't need the threat of eternal damnation to inspire us to act decently.
As an agnostic, I don't see why a belief in God is necessary in order to want to live a moral life. I can see the benefits of the Golden Rule regardless of whether you think someone will eternally reward (or punish) you depending on how you behave.
And I have secular friends that I think are perfectly lovely people, so I'm obviously not convinced that without God we are all just awful.
I will say, though, that when secularists insist religion is the only reason anyone would be pro-life, they sure do reinforce the "atheists have no morality" stereotype.
I'm against abortion because I recognize the fetus as a member of our species and I believe human beings should be valued and protected; at minimum, I think it should be illegal to non-defensively kill someone. I don't consider any of what I just said to be radical, and I don't see why any of what I just said would require religious faith in order to make sense. From the pro-life perspective, when people insist you have to be religious to be pro-life they're insisting that you have to be religious to value humanity and/or to think it's wrong to kill others. Great.
But I understand that there's a disconnect here. Many pro-choicers make a distinction between human beings and people, and while the fetus is a human being, they will insist the fetus is not a person. A pro-choicer could believe that all people should be valued and protected while all fetuses can be killed. So, from a pro-choice perspective, the idea that you must be religious to be pro-life is really the idea that you must be religious to believe the fetus is a human being of moral value.
I still think it's a little sad that some secularists believe you have to be religious to value all members of our species...but I guess it's better than thinking you must be religious to think, you know, killing others is bad.