It's called trying to put yourself in someone else's shoes. Call it an intellectual exercise. Very often it is important to think outside of one's accustomed way of thinking. I was never on a debating club or anything like that, but it is common to have to have to argue for a position with which one disagrees in order to understand it. You do not have to agree with someone's point of view in order to understand it.
Furthermore, it it necessary to come up with non-religious arguments against abortion.