"Praying for the dead" in xian terms is only further linking curses to the deceased soul so he can be further damaged in his next reincarnation. In any enemy claws, there's no escape, not even by death.
We on the other hand can help, communicate and maintain a certain degree of relationship with those deceased to us, but it matters not only your degree of advancement but also that of the deceased, in terms of communication. It is not different of how a friendship is maintained in terms of reciprocal interaction for those close to us that died.
If a person is not open and advanced enough, death to him is just a night dream up to the next reincarnation.
Gods are here to help with these matters as far as their offices go, and they can be approached to resolve matters and help maintain a natural course of things.