Is the body of Christ separated? Does your leg need to hear your arm to be part of one body? Does one part of your body become ill while the other is healthy? Can you have compassion without words?
Do you say the creed: "I believe in the Communion of Saints"?
When you prayer to humans in Heaven, do you receive a response from them? Can they provide comfort to you, like the Holy Spirit does?
Certainly the body of Christ, that remains on Earth, is unified, but there is nothing in scripture that suggests we can communicate with departed humans. In fact, scripture strictly forbids us from communicating with any spirit that has left this world, except for The Holy Spirit.