CAN THE DEAD TEACH THE LIVING?
I have thought quite hard about this many times, because I have known people who have lost someone they love dearly, and are desperate to reach them in some way.
As far as I can see though, the answer is no.
Luke 16:19-31 says it quite clearly.
A rich man ended up in hell for ignoring the poor. When he asked God to send the poor man he had ignored, (who was now in heaven), to help him, God said no, because there is a great chasm or gulf fixed between heaven and hell so that no-one can pass from one to the other. (Gulf in my dictionary means, 1. A partially landlocked part of the sea. 2. A deep chasm/abyss. 3. An unbridgeable gap).
When Lazarus asks God to let him go and warn his brothers of their impending fate if they do as he had done, God again says no, because if they will not listen to the warnings of Moses and the prophets, they would not be persuaded by someone rising from the dead.
I take this to mean that the dead cannot interact with the living because it would serve no purpose.
Also, God sent us Jesus.
Jesus is the way, the truth and the life, and no-one gets to the Father except by the son. (John 14:6)
2 Peter 2:2 warns us that some will malign the way of the truth by their immoral lifestyle.
So I think we need to be very careful about who we trust.
It is very tempting and maybe even exciting to think we can reach or interact with loved ones we have lost, but my personal feelings are that it is not possible.
We have to remember that a third of the angels chose to side with Satan, and may be able to use their knowledge to misguide mankind in an effort to keep us from seeing our Lord. (But remember that this means there are two thirds of the angels working for us as ministers of Gods will).
As always, this is how I understand my God. Don't take my word for it, look for yourselves. see what you think.