I have always loved the idea of the "cloud of witnesses" that have come before us as Christians. It comes from Hebrews 12:1, which reads "Therefore, since we are surrounded by such a great cloud of witnesses, let us throw off everything that hinders and the sin that so easily entangles, and let us run with perseverance the race marked out for us." I love the idea of being surrounded by the people that we have loved and lost. It makes me feel that they have not just gone before me, but that they are always with me. I think I first became aware of the phrase "cloud of witnesses" when I heard the Mark Schultz song with the same name, so I always think of it when I hear the phrase.
So on All Saints' Day, I remember all of the witnesses that are surrounding me with their love even though they are no longer with me.