Ethically, this is one of the most challenging questions we face. Are we truly more than the sum of our biological parts? When does life begin? When do we become a human being, rather than a lump of cells?.
What does science reveal? In the laboratory, eggs and sperm are brought together. But it is not as mechanical as one might think. Fertilization doesn't always take place, and science can't always explain why not. Scientists have developed ways to force the sperm inside the egg, but this doesn't always work either. Some eggs are successfully fertilized, but fail to grow and divide. Some become embryos, but fail to implant in the uterine wall. Others successfully implant, but spontaneously abort later on, for no discernable reason. The will and desire of both scientists and parents are powerless to alter the course of events they set in motion. Clearly, there are no clear rules that govern or predict the outcome.
So, what are we to make of it?
Personally, I believe that God creates each unique human being with a soul, and it is God's creative action that enables fertilization to take place, cellular division to proceed, and implantation of the embryo to complete. Therefore, I believe that, ethically, life begins at the instant of the first cellular division of the fertilized egg.
So, does that mean that God intentionally creates human beings that will not grow to maturity?
Yes. I believe that Scripture is clear that we live in a broken world, and in that world our bodies fall prey to illness and injury. Science is quick to blame environmental factors and genetic mutations for many illnesses, and more are discovered every day. God as a purely good creator will continue to create human beings despite our broken world, because it would be unfair to deny creation to the unborn for problems they did not make. To an eternal God, the time a human being spends on earth is short, compared to an eternity in heaven spent with God. Therefore, unborn children, regardless of whether they fail to implant, spontaneously abort, or are aborted by choice, are not a mistake, but a deliberate creation of God. The failure of any of those unborn children to be born is the result of sin and brokenness in the world.
Are you saying the parents are to blame for a miscarriage?
No, not at all. A miscarriage is a tragedy - the death of a child. It is not the result of the parents' sin - it is the result of the collective sins of mankind since the Garden of Eden. The release of PCB's into the environment, radiation damage from a weakened ozone layer, chemicals in the water table - all these things flow from sins of greed and lying and stealing. Consider the money that goes into insurance against theft - we all pay for theft, whether we steal or not. It becomes part of the environment, and affects everything in subtle, insidious ways. So, we are all affected by not only our own sins, but the sins of others. Sin is what makes the world so broken. And sin is what kills unborn babies.