Regarding the issue of life in the womb, and my reading of Scripture on this issue summarized briefly:
(1) I will defer to the scientists on what their view of life is and is not, and when it does and does not begin. They have their presuppositions about a lot of things that color all they see, and the great weakness of the scientific approach to knowing anything, in my view, is the huge blind spot about how presuppositions (which come before any experiment or hypothesis or theory) color all they later see. If you have the presupposition, for example, that all that is real can be proven by the scientific method of falsifying a null hypothesis, then you miss out on a lot of the really good stuff in the world like love, beauty, justice, truth, Jesus--while these are all real, they do not validate their own existence under a microscope. There are other kinds of knowing.
(2) If, for example, you presuppose that truth coheres with itself, and corresponds to experience, and that it is stranger than fiction, then you could equally believe that life begins at conception, or that my life began when my mom and dad met, or that my life began when my Spanish conquistador great grandmother married my Blackfoot-German great grandfather (by reductio ad absurdum argumentation).
(3) All that said, my concern is different. The question is not when life (Iiving cells) begin to form (clearly, at conception), but when a living soul is born according to scripture, AND the scriptural difference between murder and killing.
(4) With regard to when a soul is born to life in my reading of the Bible:
(a) The Hebrew word ruach and the Greek work pneuma in the Old and New Testaments are correctly interchangeable translated "breath" and "spirit." This is based on the presupposition in much (most?) of the ancient world that a human soul is born when you breathe (your spirit/breath comes into you), and it your spirit leaves when your breath leaves, because they are somehow mysteriously and inseparably tangled together, physical and spiritual.
(b) There are numerous examples of where the Bible describes the death of a person in terms of "they gave up their spirit/stopped breathing." No one would have thought otherwise. It is never argued for in the Bible because it didn't need to be--it was so understood that the structure of various languages all support this same connection of breath with spirit with a human soul being born and then leaving to another place with the breath that leaves.
(c) The "life begins at conception" reading of the Bible has little to go on by comparison. This reading claims "God knew me in my mother's womb" is proof that abortion is murder, but that has to overlook the writer's intent to express, "I am deeply and truly known by God from beginning to end in a way no one else knows me. And, how does this apply to the issue of murder? The Bible also says that God knew me before there was time--if we make the same application to the issue of murder as the womb scripture then we have to argue that every murder is a multiple murder like one of those time-traveling Hollywood movies: if you killed my grand-father you also killed me and so you are a multiple murderer and qualify for the death penalty in many states (don't get me started on that).
(d) When I read the Bible, there is nowhere to be found a discussion of the issue of abortion. Jesus does not mention the issue. Nowhere in the New Testament is the issue mentioned. Best we can get to there from both sides is an argument from silence.
(e) The attraction of the life-begins-at-conception reading of scripture--and I speak as one who had argued it most of my Christian life, but no more--is a PHILOSOPHICAL argument masquerading as a scriptural reading. And it is attractive because It is more consistent, philosophically speaking, and avoids the fatal flaws of the viability argument.
(f) To summarize, in my reading of the Bible, a human soul is born at birth when they start breathing (the "spirit" enters into them), and human life ends when we stop breathing/give up our spirit. I don't doubt that "science" is surely right that what is in the womb is alive and growing, and there is no question that it is on its way to being a breathing human, all being well. I don't doubt that God has always known me, and has foreknowledge of me before I was born--I receive that message that I am known intimately and loved deeply, as are each and every person.
(5) The scriptural distinction between murder and killing is reflected in every legal code since. Both killing and murder are very serious, but they are not the same. There is no question that abortion is killing. I doubt that it is murder. When someone aborts, in my view, they are killing their fetus but it does not rise to the crime of murder, because the living fetus does not yet have a human soul (that doesn't come until breath). Abortion is has serious consequences, physically, emotionally and spiritually, but it is not murder.