There are certain things that I hear or read that really rub me the wrong way; things that immediately strike me as being wrong, but are, in my opinion, so obviously wrong that it takes conscious thought to figure out why. One of these statements is, “God is pro-life.”
It seems to me that there are a lot of flaws with this argument even if you are a deeply religious Christian. I'm not terribly familiar with the bible, but I do know that a lot of people die, with God's express approval. I know there are stories where he has demanded the death of innocent people, and in fact the most basic claim of Christianity is that Jesus – an innocent, godly man that we're all supposed to model our behavior after – died for our sins.
This does not argue that God is pro-life, not even for innocent people. He certainly isn't for keeping sinners alive, not if you believe in the bible. It's full of stories of people doing the wrong thing and getting killed for it.
Of course, in the pro-life argument, they're specifically talking about unborn children, who most people agree are innocent (though maybe not the people who believe in original sin - I don't know about that). In many cases that innocence is used as a reason not to “kill” them. So let's talk about innocents in terms of living and dying, and with the concept of God as the all-powerful creator in our minds.
Babies are stillborn or miscarried all the time, even though, today, we have better survival rates than ever before. And this is not limited to human beings, but experienced by every species that gives live birth. In species that lay eggs, some of the eggs never hatch, even when they've been fertilized. The fact that it happens to all species indicates that it is not some kind of punishment for the sins of humans, so that argument is out the window. And God-the-creator is, by definition, the one who made us the way we are. So if he was against pregnancies being terminated prematurely, why would that happen naturally? As an all-powerful deity, he could easily have made that impossible.
But I think the worst part is that those same people are the ones who claim that God is inscrutable; that it is impossible for human beings to understand why God does what he does... and yet claim to know what he wants, without being expressly told. Unless I am mistaken, and somewhere in the bible it says God hates abortions, but I think it would be quoted all over the place it that were the case.
No, I think their best chance is to say that it should be God's decision; that we shouldn't play God. It's a simple opinion (one which has been used to fight all kinds of scientific developments), so it can't really be refuted – that makes it the only tactic that has any chance of success, because anyone who says “God is pro-life” certainly won't argue on pure moral or logical grounds. Even if they could win.
As a final note, let me say that I personally will never have an abortion. But that doesn't matter; it's completely beside the point... because this isn't a pro-choice argument. It's simply a criticism of the statement “God is pro-life”, because I don't think people should ascribe their own feelings to a deity which is (according to humans) inscrutable by nature.