In the raising of Lazarus from the dead, Jesus proclaims that he himself is the resurrection and the life. These things are not abstract promises, but are fully embodied in Jesus himself, which will be completely revealed to all through his death and resurrection into his glorified state. The Valley of Dry Bones becomes an emblem of this reality about Jesus for we all who have trusted in him will likewise be raised to new life from the grave. That life is hidden for now, but will also be revealed to all in the end.
Image: The Vision of the Valley of Dry Bones, Gustave Dore, Public Domain. Image location: https://www.wikiart.org/en/gustave-dore/the-vision-of-the-valley-of-dry-bones-1866