I don't believe in life after death. But it would be more accurate to say I don't really believe in death at all.
Every atom we're made of came from somewhere else. And when we die, they just get reassembled into something else. That's not a belief, but a law of physics. In that limited sense, we're all immortal.
But I don't believe that my lost loved one's personalities are out there somewhere intact. I imagine that death is much like before we were born: nothing. When I think about the people I've lost, I miss them. I wish I could see them again. But mainly, I'm glad they existed at all, for however long I got with them. The nothingness doesn't bother me at all. If anything, I think it makes the fact that any of us exist for any time at all more beautiful. Every beautiful thing ends. If it didn't, maybe it wouldn't be beautiful any more.
That's my take, anyway. You asked!