There is no evidence for the existence of God or creationism. Since we cannot prove that God exists or that he created life, there is nothing that makes life inherently sacred. It is not unethical to abort a fetus because life is not sacred and not worth protecting.
Religion is not a guide for morality; "morality and a religious value system are two distinct kinds of value systems or action guides."
Therefore, while religion can be used to guide an individual's idea of ethics, religious convictions that deem abortion unethical do not extend to all people.