We do not believe in ghosts.
We believe that a huge part of us survives in the memories of others and in the state of the world due to everything we did during life, especially bearing children and making friends. We believe our spirits* partially survive in the memories, spirit worlds* of our survivors.
We do believe that resurrection is a possibility, but we'll believe it more, when we actually see it, and do not belie in resurrected beings, gods, or any thing that hides.
For a definition of what we mean by "spirit" and "spirit world" see the definition in the current leading expert scientific consensus "Representational Qualia Theory" statement