Almost all religions in History, remember their "Loved Symbol" being alive and with all the perfection details that, that living being had when was alive, he/she gave to them, as values that guide their religiosity or spirituality.
Christianity and others inspired by them, remembe the loved one in a suffering moment and using technique to celebrate that are a bit contradictory against all other religious groups around the globe and from history. Jesus Christ is remembered in Churchs as (who was cruxified fall all the bads that the believers did), putting Christian believers in a position where (cruxifing others) is the only way to love them, while being thankful of someone death for something that this someone (Jesus Christ) didn't chose to do, is as well a Criminal perspective, which all criminal groups would LOVE to have for them. [C kill A and B go arrested as it was C]
Gladly Justice systems don't always behave like that, while there are many examples that we cannot deny that justice behave like that.
(Cultural Influences) - Make sense to me, since is all about Memories
Drinking the Blood of the Ones we love is a bit Vampiric, because Only a Vampire would be greatful for someone death by celebrating his death by drinking his Blood. Eating the body of the Ones we love is a bit Canibalistic, because Only a Canibal would be greatful for someone death, by celebrating his death eating his body. Even if the Blood of Jesus Christ is only Wine and even if the Body of Jesus Christ is only Bread, the style that is used to remember this person that gave important values for actual societies, is totally different from all others that remember their loved ones as someone alive in their Perfect Moments of Time.
I really think that Celebrating the Birth of any Child is good and let me believe that Christmas wish to project that notion for their children, while all other religions in the world, that love someone who inspire them, don't celebrate the Death of their loved ones, because for them they are Eternal "like God is", while if they are not, they will never Die in Memory.
Christian societies are full of discipline education that punish those who do something wrong, sometimes (a few years ago, while conscience is beign changing for better) being violent against children and non-children, including animals(with brain), that have total conscience of reality in a Sensitive way, and not in the Rational way, like almost all humans are able to be.
As I like to say, I am what the Universe chose me to be, not a choice imposed to me
In fact, the only moment that I wish to celebrate the death of someone, is when that someone represent something bad to me, all others I never celebrate their Death but only being Alive like any free child.