Were Elijah and Moses dead or alive when they were with Jesus at the Transfiguration?
Nor was Jesus asking Moses or Elijah to intercede with God for him. The transfiguration is not related to praying to the dead. In fact, we have other scripture, from Jesus, no less, that emphasizes the futility of it.
Furthermore, you have no way of knowing where the departed soul that you "talk to" went. If they have fooled you on earth with their piety and were not sincere, or were not elect,then your prayers are not only in vain, but something worse. Maybe you are "talking to" a lost soul.
Pardon me for not understanding your doctrine, I just cannot comprehend praying directly to the Father, through His Son. This is the tradition that the bible teaches us.