A funeral is to honor the departed and to comfort those who remain. More than any other ceremony, this may require acceptance of a spiritual element in the ceremony. It is probable that at least some of the mourners will believe in a Supreme Being, and they are as deserving of whatever comfort can be provided as are skeptics.
Reverend Troy Rodriguez has provided a sample funeral service. Feel free to modify it and add to it according to the needs and wishes of the family.
Alternatively, this ceremony has been developed by The Right Reverend Tanya Hannis