Is it normal for a dead relative to appear in your dreams?

Shortly after my grandfather died a few years ago, I had a dream that I still remember vividly. I was at his funeral, crying my eyes out, mainly because I never got to say goodbye, which was how the actual funeral went, but then his still-living brother sat down next to me. After that, my great-uncle tore off his face like a mask, revealing the face of my grandfather. He told me not to cry, that everything was alright, and things along those lines.

Now I was just wondering, is this normal? I've had dreams that have included him since then, but none that were anything like this; most of them, he was still alive in. I haven't had any dreams with other dead relatives in them, either, even though I may have been a bit closer to a few of them. And I'm not exactly religious, either; I don't believe in ghosts or angels or anything. But this dream has had me wondering.