Here’s the next little bit from Norman Geisler’s unremarkable, unremarked on, conservative white evangelical book Ethics: Alternatives and Issues, 1975 edition. Guy could be a bit repetitive.
B. Abortion Is a Very Serious Activity
Abortion is not murder, but it is a very serious activity. Artificial abortion is a man-initiated process by which one takes a potential human life. Abortion is a much more serious question than birth control, which merely prevents a human life from happening.
1. Abortion Is Less Serious Than Murder — Murder is a man-initiated activity of taking an actual human life. Artificial abortion is a humanly initiated process which results in the taking of a potential human life. Such abortion is not murder, because the embryo is not fully human — it is an undeveloped person. By aborting, the human life is nipped before it buds (assuming birth begins the budding). If a life must be stopped, it is obviously better to stop it before it ever really gets started. But the question is this: should a human life ever be stopped before it really has a chance to get started?
2. Abortion Is More Serious Than Birth Control — Birth control is not essentially wrong, for it merely prevents some life from occurring. Abortion, on the other hand, takes an undeveloped life after it has occurred. Since God is the Author of life, it is a serious thing to stamp out a life which He has permitted to come to pass. Once must have a good reason for extinguishing what God has kindled. The human embryo will develop (all things being equal) into an immortal, never-dying person. To snuff out what could become a human being is not an amoral act. There are serious implications to an act of man which strikes at an act of God in initiating a life.
In begetting children parents are serving as a channel through which God can create life. It is wrong, of course, to block the channel completely so that no life can get through (as in complete birth control of the whole race). But it is not necessarily evil to limit the amount or kind of flow through the channel (as in proper birth control). However, once the flow of life has begun it can be definitely wrong to snuff it out without ever giving it a chance to develop. Conception is a prima facie case in favor of giving the undeveloped person a chance to develop. One must have some higher moral duty which demands abortion before he initiates it.