A funeral is often perceived in the context of the deceased, mostly in following the thought process of what they would want were they there making the decisions during the funeral arrangement. And that line of thinking does serve a good purpose: putting personal touches that reflect the deceased makes them recognizable in death (This is what picking out their favorite clothes, jewelry, the makeup and hair styles, and other personal items to be buried with them does.) Making a loved one recognizable and the funeral process personalized-- and participatory-- helps the bereaved face the reality of death and the major change such a loss initiates.
Another function of a funeral is to give the family an opportunity to be supported by their community. I witnessed two examples in two different friends' lives. A man who was a respected authority figure to one friend in his teenage years had lost his wife to a brain tumor. I asked J. if he was going to the funeral, and he replied, well, I didn't know her. I said, you don't go because you knew her; you go because you want to support her husband. I did the same for a co-worker who is a dear friend. Her grandfather died, and the whole staff attended the funeral. We didn't know her grandfather, but we cared about my friend, and we went for her, to give her hugs and to show her that we were there for her.