Hitler did try, he wanted certain species to be revived. But, the problem is that DNA is just the body, and when a soul is gone, the species is gone for good too. The soul is created differently from the start, not from DNA, transferred from being to being. Therefore, it will never be possible to clone completely, or to revive extinct species. And then it is also impossible to live forever, since the soul ages. The normal way of thinking is that the body ages, but that applies mostly to people who are part of society, who hold on to things mentally. A normal person will look the same all his life, with a body of normal function, but people in society will have a body that ages then, unpleasant death also since the body gives in first. It is an old wisdom actually that the body is not from DNA but is passed on from life to life, it's just the time we live in now where the cynical decide what others will think, but they never manage to figure out how to live forever even , they just go in their own thoughts, and try to make others think the same