It is a mystery, but our souls, our very persons, existed before conception. God is not creating new souls for a new body every time at conception, as many believe. God's creative works, at least as a rule, were finished on the Seventh Day of creation week as recorded in Genesis. Everything that exists now, body as well as soul, existed in some form since that day. After creation week, the Bible says that God "rested" (or ceased) from anymore creative activity. Thus, we literally existed in some form from the time of Adam for we were all in Adam.
Reproductive cells (i.e. sperm and ovum) come from somatic cells. That means we must have existed in the somatic cells of our parents' bodies at some point. I admit, this is a great mystery. Does this mean we commit murder when we intentionally destroy the somatic cells of our body. Are we committing murder if we destroy somatic cells by scratching our nose? No. For God has not given humans the right to independent life apart from when such life actually develops (such as during conception) for that is the means by which He has sanctioned for bringing independent human life into the world.
What if we should clone a human being? Cloning is wrong. That is not how God intended humans to come into the world, but successful human cloning would be proof that the soul exists before and apart from conception. The soul may also be physical (perhaps a form of energy) but distinct from the rest of the body. Nevertheless, if we should ever succeed in cloning a human being then that human life also has equal right to become independent since the process towards full maturity has begun. This is why abortion is wrong morally, and abortion also should be wrong legally because the unborn baby's right to life outweighs a woman's right of privacy. To kill someone else whom God has given an inalienable right to life should never be a personal choice and definitely should not be supported by public or federal funds.
We have succeeded in cloning animals and animals have souls, though not created in the image of God. The same Hebrew word "soul" that is used for man is used in reference to animals in Genesis, but the translators used the word "living" instead of "soul" because they wanted to emphasize the distinction between humans and animals. Other portions of Scripture teach that animals, as well as man, have spirit. Putting it all together, then, both animals and man have spirit, soul, and body with the difference being that man is created in the image of God. Non-conscious life, vegetation, etc. have bios (life) but not soul or spirit.
These are great mysteries. Scripture says, in the New Testament Book of Hebrews, that Aaron was already in Abraham's loins when Abraham gave tithes to Melchizedek. We cannot go further than what God's Word allows. The secret things, indeed, belong to God.
According to the Bible, murder is when you kill someone with malice. That is the definition in the Old Testament for murder. Jesus, in the New Testament, says that hating your fellow man is equivalent to murder in God's eyes. Hatred then is malice. What Jesus said about hatred defines the Old Testament meaning of malice.
Many who support the right to abortion do so not because of malice towards the unborn but because they do not wish to see an unwanted or severely deformed child enter the world. That doesn't make abortion moral or right, but are we correct in labeling all abortion rights people as being murderers.
What about the many racists in our society? Aren't they murderers according to Christ's definition of hating your fellow man as being murder? Our nation's economic foundation was built on the back of African slaves. Then, after slavery, there was segregation of blacks and whites, all of this based on hatred and contempt of other fellow human beings because of differences in physical features.
Abortion is wrong, but the greater sin in God’s eyes is racism, the hatred of our fellow human beings because of how they look.