This is how the world works I guess.
Murder is a tradition that came into being when one Son of Adam killed another son of Adam, his brother. The first human who died, was not a natural death, but it was murder, thus the tradition of murder came into being and still continues today.
As for war, it will keep on continuing, till Dajaal comes and is defeated by Hazrat Isa, it would be the last of wars, no war would come after that.
As for fight between Muslims? Umm,I heard something about it but I don't know its authenticity.
Regardless, in the end , this life is a test, we are all given a scenario and role to perform, in the end we die, go to grave, resurrected on the day of judgement, then either sent to heaven or hell, based on our life, that is the real reality.
Your true destination either lies in heaven or hell, and you only get one chance at life to make choices.