actually, u need similar beliefs in order to be able to really bond. unless u just wanna superficial relationship where u just stick to simple matters. but life isnt simple. in times of crisis, it could be ur shared beliefs that gets u thru together. ive seen how friends desert u in such times, not just coz they werent true friends or lacked loyalty or were uncaring, but coz they didnt share ur heart (i.e. beliefs), and u were in a whole different world as far as they were concerned. and i dont mean just similar experiences either (tho they can contribute to ur beliefs).
and where there are differing beliefs, it always means that one or the other has wrong ones. we all like to think ours arent wrong, but the truth of the matter is that some of them, or many of them, are. truth is not relative. God knows what's right in every situation, and He wants us to find out. we were wrong when we didnt believe in God, and we're wrong about certain things even now. (of course in some cases both parties may be wrong.)
and within a relationship, when one is right and the other is wrong, then its their business to find out which belief is right and not just go on as if "this one's right for me and that one's right for you" is OK. Whether that means conflict or not, if u really cared about not just ur relationship but having the truth itself, whether for u or the other person, then u gotta deal with that. for most ppl that often leads to conflict, coz there's lack of respect, spiritual understanding etc. its ur choice what kind of relationship u choose to be in, whether u stick with one with differing beliefs or not, but i think the bottom line is that u must care about the matter either way. and deal with it within or outside of the relationship (that is, if you wanna have one).
its hard to have a truly deep and lasting connection even with friends who believe differently (in the end), so how harder is it to have with someone closer than that. If you read Paul's writings, you see him always encouraging all the believers to be united in mind and spirit and that isnt apart from their beliefs (or else why did he go thru the trouble of teaching them and correcting them so much?). "how can two walk together unless they be agreed?" and its fine to agree to disagree, as seems to be a favourite here, when things are relatively good, but when heartache and trouble come you'll see thats its hard to walk together then. you'll see that it does matter very much.
if you believe something thats wrong, you're believing a lie. how can you, as one who claims to care about your brother/sister, not care that they believe a lie and say that thats OK? or how can you not care if you yourself believe a lie? which is what you do by saying that it's OK if what we believe is different.
which goes back to what i said eariler. you can either struggle and work thru ur beliefs to achieve greater unity of mind, or ditch that person and find one who's as enlightened or blind as u. depends on how much u beileve that beliefs are important in the end, doesnt it? everything, incl. how you accept my comment, depends on what u believe, doesnt it. u live according to what u believe, so how can u live well with someone else who believes and therefore lives differently (wants to take different paths from you in certain situations...). Its like being tied to someone in a three-legged race, who insists on going left when you're meant to go straight. if u've ever tried it, u'll know the difference in speed, comfort, etc, depending on your partner. u can survive with one that's out of step with you, of course, but the difference is b/ween having either a good or bad relationship in life.