Love hasn't been replaced as much as it has been appropriated by the party, as has loyalty. Whereas once people within a family had love for one another, now people are expected to put their loyalty to Big Brother and the party above all else. That is why children are feared by their parents and why people are allowed to marry as long as they have the proper attitude towards sex (they are not supposed to like it, but are supposed to do their duty for the party). There are not supposed to be any intimate relationships because intimacy and love divide people's loyalties. The party could not have absolute control over people who put their loved ones and family first. As for sacrifice, that has been eliminated, for no one has any reason to sacrifice because no one has anyone (apart from Big Brother, that is) that he loves more than himself.