Like love, friendship is not conditional. If there are conditions set at the pretext of the forming of a relationship you are automatically exclude the nature of that relationship be one of friendship or love. With love and friendship, a difference of opinion cannot be a deal breaker.
By definition, faith is "something hoped for." Faith is belief and belief is an opinion. Could you imagine a couple in a romantic relationship ending their relationship simply because one party says vanilla is the best flavor of ice cream and the other says its chocolate? Could you imagine two people being best of friends, growing up together, go through school together, suddenly ending their friendship because one is a Dodgers fan and the other is a Yankees fan?
That's exactly what Jehovah's Witnesses teach. Spouse, child, sibling, best friend - all these close relationships are meaningless if you change your mind about your opinion that Jehovah's Witnesses are the one true religion and all their teachings are true. Jehovah's Witnesses have to be honest and accept the fact that cannot be a Witness and be in love with someone or have a friendship with someone.