Personally, I find times of bereavement to be the worst moments to discuss religion, especially subjects such as the afterlife. I've got to go with the sentiment that there is no reason to state your beliefs unless asked. If the subject of the afterlife came up, however, I would just say that you are unsure about it. It's less of a lie than saying you believe in it, and it will keep you from getting into an over emotional argument about the state of a loved one no longer living.
Even if the open windows of science at first make us shiver after the cozy indoor warmth of traditional humanizing myths, in the end the fresh air brings vigor, and the great spaces have a splendor of their own - Bertrand Russell
