He's against abortion because he says he's religious, and that's it.
And his post is missing because I've deleted it for being pointless. Unless he's going to tell us what he thinks rather than what the book tells him he should think, I'm not going to let him post stuff that doesn't contribute to the discussion; everybody is entitled to their own opinion, but if they're not going to tell us why, I'm not going to keep it here either.
Last warning
everybody, this is D&D, get serious.
Back on topic:
Plants as living beings argument - now we step into the realm of consciousness; people argue plants are not aware of themselves, nor are they capable of experiencing pain or pleasure (there are some who argue the two are inter-related; only sentient beings are capable of experiencing pleasure or pain, but that's debatable) living non-sentient beings merely carry out basic biological functions. This argument is used by people to justify "killing" living beings such as plants or lesser animals such as insects.
It's important to realize that a great number of people do in fact acknowledge that they are "ending lives" when they kill plants or what not, but they see it as a necessity in order to survive, and readily assume everybody would agree, since there isn't much of an alternative to survive otherwise.
There's also the much simpler argument where people simply argue it's wrong to kill something with a brain... but... yeah... that's all there is to it, it's the same argument about consciousness as above.
In terms of abortion though: If we're considering the argument of consciousness, then it's logical to assume it'd be OK to abort a baby before it develops into a fetus, since it wouldn't even be any more aware of itself than a plant, but that period tends to be pretty brief.