People have a fear of one of three things, the actual moment of death, possible pain and suffering in the time period before they die, or they fear the unknown of the afterlife, and if you break that down and address them individually it can go a long way.
For instance, when you talk about the actual moment, the heart stops, you pass out and that’s it, pain free.
Live, Love, and Let Go: A Doctor’s Insightful Approach to Living and Dying.