How does having your own son murdered repair the damage in a relationship?
In a culture that relies on animal sacrifice and the concept of the scapegoat - an innocent creature suffering for the wrongs of others - it actually makes considerable sense. Throughout their history the Jews lived with the idea of penal substitutionary atonement (though they didn't call it that), whereby their wrongdoing was atoned (made amends or reparation paid) for by an innocent, perfect substitute, thus repairing their relationship with their creator. The only way for a deity to fulfill that concept, thus making any further such substitutionary deaths unnecessary, would be to provide their own child as a once for all sacrifice, which would ensure that the opportunity for humanity to return to the relationship that they'd damaged in the past was open to all the Jews - but also to all humanity, and that it would be available to all, for all time.
That is why we, as a nation that once regarded ourselves as a Christian nation, don't feel the need to indulge in animal sacrifice. Mind you, if one reads the media, it does appear that we still rather like the substitutionary atonement idea, with the way that so many seem quite happy to offload the blame for wrongdoing onto other people who are likely perfectly innocent of whatever we want them to be guilty of (even if they are guilty of other things).
