If reincarnation exists, justice can be vindicated by its reference to previous and future lives. This line of reasoning even appeals to Christians. If you come in at the chapter in which the villain beats the hero to a pulp, of course you will ask the old question. You may even put down the book at that point and join forces with those who call life absurd, seeing no justice in the Universe. That is because you are too impatient to go on to hear the rest of the story, which will unfold a much richer pattern in which the punishment of the wicked and the vindication of the righteous will be brought to light.
Many people are disappointed with their lives.
They see many of their ambitions unfulfilled. They acknowledge that they have failed in important relationships. They feel that, when given the opportunity, they would like to re-live their lives in a better way. This gives rise to the dream of a second chance. Again, reincarnation offers this promise.