One of the problems in the Church today is that the majority of Christians do not know how to defend what they believe; this is precisely why Theresa and I will be doing a relatively short series on pro-life apologetics. Later on we will get into the more complicated arguments for bodily autonomy, but this post, as the title states, will be about the humanity of the unborn.
The vast majority of pro-choice people you will get into a debate with are going to make arguments about rape, finances, and things like that. When they ask things such as "You really want to force a woman to bring another child into the world who she can't afford to raise and will grow up in poverty?", they are making an assumption, and this assumption is that the unborn are not human beings. They cannot prove it; they are only assuming it. The first thing you should do when these questions/statements are thrown at you is use a technique called Trod Out the Toddler. All you have to say is, "I have a two year old in front of me. His parents want the right to kill him because money is tight and they need more money to feed the five year old. Should they be allowed to do it?" If you are talking to a normal person with at least a little bit of a conscience left, their answer will be "No, you can't do that!". When you ask them why there is no moral justification for killing that toddler and they say "Because he's a human being!", your reply needs to be, "But if the unborn are human like that toddler, should we be killing them in the name of economic hardship?". The pro-choice person will most likely try to argue that the unborn aren't human and that killing a toddler is different; but IS there any difference? They have to answer the question "What is the unborn?" before they can answer the question "Can I kill the unborn?".
When a pro-choicer tries to say that the unborn are not human beings, ask them if they would like to take that up with biology.
"Although human life is a continuous process, fertilization is a critical landmark because, under ordinary circumstnances, a new, genetically distinct human organism is thereby formed." (O'Rahilly, Ronan and Muller, Fabiola. Human Embryology and Teratology, 2nd edition. New York: Wiley-Liss, 1996, pp. 8, 29).
"The zygote is human life...there is one fact that no one can deny; human beings begin at conception." -Landrum B. Shettles "Rites of Life: The Scientific Evidence for Life Before Birth" Grand Rapids, MI: Zondervan, 1983 p 40. (Landrum B. Shettles, M.D, P.h.D. was the first scientist to succeed at in vitro fertilization)
But even if there was no proof that life begins at conception, or if no one really knew when life began, as pro-choicers like to argue; should we continue to kill the unborn without knowing for sure what they are? Scott Klusendorf uses the analogy that if you were driving home one night and saw what appeared to be an old coat in the road, you wouldn't just run it over! You would err on the side of caution and make sure that it wasn't an old man who had had a bit too much to drink and then collapsed in the street. If you were about to blow up a building to put a new one in it's place, but you weren't 100% sure that there were no living human beings inside, would you blow it up anyway? Of course not! Again, you have to answer the question "What is the unborn?" before you can answer the question "Can I kill the unborn?". Science provides massive amounts of evidence pointing to conception as the beginning of human life, and because of that we can answer the question "What is the unborn?" by saying that the unborn are distinct, living and whole human beings.