From a Buddhist point of view, the actual experience of death is very important. Although how or where we will be reborn is generally dependent on karmic forces, our state of mind at the time of death can influence the quality of our next rebirth. So at the moment of death, in spite of the great variety of karmas we have accumulated, if we make a special effort to generate a virtuous state of mind, we may strengthen and activate a virtuous karma, and so bring about a happy rebirth.
From the scientific view, the theory of karma may be a metaphysical assumption -- but it is no more so than the assumption that all of life is material and originated out of pure chance
Many times man lives and dies between his two eternities: that of race and that of Soul... A brief parting from those dear is the worst man has to fear... Though grave diggers' toil is long... They but thrust their buried men back in the human mind again.
Still others commit all sorts of evil deeds, claiming karma doesn't exist. They erroneously maintain that since everything is empty, committing evil isn't wrong. Such persons fall into a hell of endless darkness with no hope of release. Those who are wise hold no such conception.