Religious Opinion in Class / Opposing Views

Alright, I know this is a heavy topic and all, but should religious ideas / personal beliefs be discussed in class? Surely in a debate that would present a biased view, and alter the balance between the two sides. In my Spanish class we were discussing Abortion. Although both sides of the issue gave decent reasonings for what they believed, there was always one student who said that babies should not be killed because it is bad "according to the bible." I don't mean to go against any beliefs, especially christianity (seeing as I'm raised in a christian enviroment) but doesn't that take it too far? I really don't see any way to argue "because it's the christian thing to do". I don't want to say "well, since I don't believe in that, it MUST be okay to kill babies" because then it will seem as though I have no sense of moral justice. Should it even matter if I say that or not?

And just because it relates to what I said above, is it really all that okay to express your opinion and not care what others think? Without thinking, most people would say yes, because there will always be those who like you for you, etc etc. But what if you don't like these people that like you, what if it means giving up your significant other? Then is it worth expressing your personal opinion? What if it means being shunned from society, or hated? Would you go to live on your own? Modern psychology teaches us that this would be a terrible form of torture, for humans have a NEED, a NEED to belong. But we also want to make ourselves unique to others, and have different views on how things work. So really, is it okay? Is it a good thing to not care what others think about you?

Thanks to those who read my wordy rant, and thanks again to anyone who submits their opinion. I will read them all