Why can't the departed saints pray for us?

It's a good question. We ask our friends here on earth to pray for us from time to time. Why not ask our faithful departed friends to pray for us?

Douglas Wilson suggests (in What Mary Knew - A Sermon on Luke 1:28 Christ Church – Moscow, ID Sermon #1754 – A.D. Dec. 15, 2013) one reason. To do so requires you to attribute a functional omniscience to the faithful departed. For example, you would ask your friend in China to pray for you via email, not via telepathy. And you cannot email the dead. So asking the dead to pray for you is a mistake. And it is especially undesirable as it attributes the the departed saints something which is proper only to God.

Wilson also points out, by the way, that the youngster Mary was an well-educated adept Bible student and an accomplished Systematic Theologian with wonderful poetry at her fingertips. She could have been an excellent preacher. In fact, for 30 years, perhaps no one understood Jesus and his mission better.