It's just that Christians are against killing human beings without a good enough reason. Self defense is a good enough reason, for instance.
Christians didn't invent biology - well, I guess they did, to a considerable extent. But not on the basis of being Christians; it's just that Christians believe that truth and knowledge is worth seeking, and so Western civilization gave birth to science. Science caused the study of biology and reproduction, and also developed the microscope. This is how scientists - in the 19th Century - learned how conception takes place, and what constitutes a new individual of the species.
That is when people - Christians and others - began to see the problem with abortion even in the early stages.
Regarding your Bible citations: You know that most of your citations are not even relevant to the question of abortion; and those that are relevant are taken out of context, so they don't say what you suggest they do.
I'm not going to go through all these quotes and discuss them, when you have not bothered to do so.