Today almost no serious scientist would dispute the fact that the preborn are living human beings. The following quote from a commonly used embryology textbook will serve as proof:
“[The zygote], formed by the union of an oocyte and a sperm, is the beginning of a new human being.”
–Keith L. Moore, Before We Are Born: Essentials of Embryology, 7th edition. Philadelphia, PA: Saunders, 2008. p. 2.
Abortion would not be “necessary” unless there was a living growing human being in the womb. Its very purpose is to end that.
We all have the innate knowledge that killing innocent human beings is wrong: it was written on our hearts from the beginning. God has set his special stamp on human beings when he created us in his image. This gives us our inherent value and is the reason that any sort of murder (including abortion) is wrong.
Whoever sheds the blood of man, by man shall his blood be shed, for God made man in his own image.
Genesis 9:6