As an atheist, I'm genuinely against any form of violence against an individual. Even going as far as to be against any form of killing in war. However, the difference between being against killing and being against abortion is in the development of of the body. A fetus at 6-7 weeks hasn't developed a central nervous system, which means it can't feel, think, or move. At this point in the pregnancy I would call it a cancerous parasite, if it grows inside of you, taking your nutrients, and you don't want the fetus, it's a parasite (kinda a leap in logic, sorry). Any point after the development of the central nervous system, the fetus must be carried to full term if it doesn't have any dangerous disabilities that would make its life a living hell, or the birth would have a probability to kill the mother).
A fetus has not yet entered the real world, and therefore has not done anything at all, let alone anything that is wrong. It is also notable that biology has proven that a fetus has human characteristics for the full duration of time that it spends as a fetus. Also, justifying the killing of a fetus in anyway can justify the killings of certain adults as well- if you justify it by saying that it cannot breathe or live on its own, then you're also justifying the killing of adults who are either on life support or relying on machines to breathe, as they can't breathe or live on their own, either. If you justify abortion by saying that a fetus isn't awake, that also provides justification for killing adults who are in coma, even though they could wake up from their coma. Another notable fact is that, ever since the U.S Supreme Court's decision in Roe v. Wade here in the United States of America, an overall disproportionate amount of black or otherwise non-white babies and have been aborted- all due to the fact that a lot of the leading pro-abortion activists at the time were eugenicists who were also white supremacists. Then, we have China, where, a One-Child Policy, meant to allow only one child per family -with the exception of multiple births at once, of course- that was aimed at reducing the growth rate of the overwhelmingly large population of the country, resulted in many baby girls being selectively aborted.
Even though fetuses cannot think, feel or move it has a future. Everyone has a purpose in this world and killing someone without letting serve its purpose is just cruel. You don't know that the baby will grow up to discover the cure for cancer or will be one of the greatest leaders in this world.
I am catholic and i feel that abortion is wrong and women who want to have an abortion need to look up what they are going to be doing to their baby before they make their decision. The catholic church is against abortion and so i am .Therefore abortions should be allowed in general.