Unfortunately, this is just mostly wrong. When religion makes claims of fact, either as part of a religious text or as part of doctrine, its conclusions are very much subject to the standards of evidence for factual matters.

Because the ideas are based on primitive superstitions about life rather than actual biology, the justification for being pro-life is almost entirely at odds with reality. All the "human life begins at" arguments are undergirded by the disproven assumption that there is something mystically special about human life. It's not something about which reasonable people can disagree. Only unreasonable people can maintain that, for instance, fertilization of an egg is a process of such magical significance that we dare not interfere in the process. Biologically, it happens all the time; without interference, lots of eggs are fertilized and don't turn into babies. The arguments also run into the naturalistic fallacy ("situation A and situation B are identical save for in case A it happens naturally, so it's fine").

To the extent that the anti-choice arguments are not based on primitive superstitions, they are strongly at odds with other widely believed principles, such as the value of individual determination (the embryo isn't an individual initially so there is no conflict).

I agree with you that the only reason to believe in the primitive superstitions is religion, which then is voided as a reason by the principle (if not the law, because the law doesn't check why you hold to your silly superstitious opinions) of separation of church and state, and that itself is reason enough for it to be a personal choice.

But I don't agree that science cannot settle the issue when it comes to arguments that are used in favor of denying choice because they are based in part on matters of fact that science has shown to be different from what the anti-choice advocates claim.