P.L.
The good news is that he'll probably outgrow this.
However, it might be a good idea to sit down with him during the day and discuss his feelings about death, heaven, etc. If he's becoming obsessed with it, telling him he doesn't have to worry about it for a long time won't do anything to alleviate his fears.
If he seems to have a great fear of death or dying, it might be helpful to have him talk with a child psychologist. These fears are normal for all of us, but as adults we can usually put them into perspective. Young children aren't quite capable of that yet.
I'd reassure him as best as you can, but I would be open and honest about death, heaven, etc. After all, dying is a part of life, and if this were even a hundred years ago, even young children would know this. Grandparents often lived with their adult children, and it was normal for them to die in the home, with their family around, including the children. Wakes and funerals were also often held in the family living room, and so children were usually aware of the entire process. Today, we tend to shelter our kids from "unpleasantness", but we'd probably be better off if we didn't.
Obviously, the book and flashlight isn't working. In fact, flashlights can cause some mighty scary shadows in a dark room. You might try songs. I used to have tapes that I played for my son at night, and I think it helped him to sleep. Of course, make sure the songs are gentle, soothing, and calming. You could even tell him they're for his little brother, and he might become more focused on helping his little brother to sleep, etc., than on his own fears. There are many children's tapes/cd's you can buy, from lullabyes to children's songs to hymns.
