Recently, my sister died of cancer. It's a horrible thing to witness, and a horrible thing to go through. What do you say to someone who has lost someone? It doesn't matter if it was cancer, or any other of the million and one ways that people can die...what do you say?
For me, I found that the best thing to hear was simply "I'm sorry," (or offer condolences) because there is NOTHING that you can say to make the loss any better. It tears a hole in your world- a large raging hole and life will never be the same. And it doesn't matter if you knew it was coming- when it happens, it hits hard.
However, a few people said some things that I just wanted to scream at them and tell them to fuck off, even if they meant well. For one thing, do not try to say things like, "she is in a better place now" or anything in that vein- "she's now part of the universe" or any other fucking bullshit like that because it does not help. Really, it doesn't.
It's a fine line of what works and what doesn't. With my sister, those that knew her, many did say that at least she was no longer suffering- and that is a sentiment I can deal with- that I can agree. Yes, it hurts she's gone, but with illness, it's torture watching someone in pain and suffering and there is nothing you can do. The drugs only help so much, and all you can do is watch them slip away. So, which is worse? Knowing the pain is over is actually a consolation, as much as you would want that person to be here, you don't want them here suffering. So that is a consolation.
But anything about where they might be, no. Just don't. You don't know for sure, and even if you believe what you're saying, it doesn't help. So shut the fuck up about that. Yes, we are all energy, we all go back to the source, we are all one, yada yada yada. But it doesn't help. So don't do it.