Why are Christians opposed to abortion? Like
@Bitter Crank said, there is no certainty when is a fetus ensouled. Christians believe that a sex is something sacred, either physical and spiritual connection of partners, where the Holy spirit is present. Therefore right after impregnation a fetus have soul and so it is a valid human. This means that Christians believe that abortion = murder.
IMO this is the right point of view, because really there is no way to tell since when a fetus should be considered as a valid human..