You can be an atheist who is pro-life. You can be a christian who is pro-choice. Your stance on abortion is just that.
I've heard numerous arguments from all sides of the abortion issue. What I find interesting is people like Ray Comfort who go out of their way to make the 180 Movie, which is a nicely put together but crappy pro-life propaganda video which compares abortions to Hitler and the holocaust. Seen that argument too. However, I find it odd how Christians who take this position (Ray Comfort included) call abortion murder and then call murder a sin.
I understand that they have a big problem with "sins." Ray Comfort has a field day with his "do you think you're a good person" test. But what I don't understand is this: In their view, since God see all sins as equal (lying about your wife not looking fat in those jeans is just as bad as raping and murdering an 11 year old girl in God's eyes), why are they spending so much time on getting people to turn against abortion? They are spending more time on one sin than another. Does that mean... that they are coming to terms with the idea that SOME issues are worse than others? You don't see Ray Comfort making a 180 movie about Theft do you? No. No you don't.
So what I'm saying is that Christians are, once again, being inconsistent. They say that all sins are equal, but spend more time defending against specific sins as opposed to treating them all equally. Make sense? Hope so.