There is a wall between those who have suffered and those who have not. With even the purest motives and the most loving heart, someone who has never suffered can not see over the wall into the world of those who grieve. The person on the painful side of the wall can tell us all about their world, and we may understand some of it, but we can't see it. We don't experience their world and can not fully know it. We can listen, but the wall is tall and we may not catch every word. It is easy to misunderstand eachother when you are shouting over a wall and this can be one of the most difficult parts. Most likely your relationship will never be the same. You may never be as close as you once were. A wall is a tough obstacle to overcome, and that's just the way it is.
It is best if the person on the outside does not try to give advice to the one inside since you have no idea what it really looks over there. Throwing food over the wall however, is often good idea. Holding hands, shouting encouragement, listening intently, praying & trying to help them physically from your side of the wall is usually appreciated. Luckily there are others on their side of the wall that have seen what they've seen. But be sure to know that even though you may not be able to help as well as the ones who have also suffered, your presence at the wall is still important. Sometimes your friend beyond the wall may disappear for a while and won't answer when you call out. It may seem easier to just leave the wall and go somewhere more pleasant, but you'll probably lose your friend that way. Eventually they'll answer. Don't take it personal. When its your turn to cross to the other side of the wall, you'll be glad you have friends over there.