A very religious Christian I know has an interesting perspective, noting the Bible does not really address abortion one way or the other. In her view, the true "human,' is the person's soul, which is what separates humans from animals - the person's soul or inner voice.
She does not be any human has the ability to prevent God from putting a soul into this lifetime, so in the event of a miscarriage of a malformed fetus, this was God's decision to give that "soul' (ie human) a better body. In this, she does not believe it possible that an abortion prevents the birth of another person because the soul is the person. Rather, it means that soul/person will just have a different body born to a different circumstance and probably different mother. Only the body (package that holds a soul) can be destroyed, not the soul itself and if God wishes that soul to live a human life, no mere human can stop it.
I'm not advocating that viewpoint, but rather pointing out that even particularly Christian people do not agree on the topic of abortion as a spiritual and God's law ethical question.