Below is a comment from Praying to Saints is Wrong!
Comment: Praying to saints or Mary or anybody who is dead is wrong and quite frankly useless. Care to know why? Because they are dead and there is nothing that they can do for any of us.
Ecclesiastes 9:5-For the living know that they will die, but the dead know nothing; they have no further reward, and even the memory of them is forgotten.
Psalm 6:5-For in death there is no remembrance of you;in Sheol who will give you praise? (now think about that for a moment…if we cant praise God in our graves-then how can dead people intercede for our prayers?)
Psalm 30:9-What profit is there in my death, if I go down to the pit? Will the dust praise you?(again, no awareness in death)
Conclusion-no man can speak to God when he is dead because he has no awareness in the grave. So with that being said…dead people (saints or not) cannot intercede for our prayer requests because they cannot hear us.
Response: Do you believe the fullness of faith and spiritual realities is revealed in the OT? Do you realize that these are probably the very same passages the Sadducees cited in their rejection of the resurrection of the dead? More light has been given to us in Christ. We know that even though our bodies die our souls live on and are eternal. So, our eternal souls are alive even after our bodies die. Even Jesus said, Matthew 22:32
‘ I AM THE GOD OF ABRAHAM, AND THE GOD OF ISAAC, AND THE GOD OF JACOB’? He is not the God of the dead but of the living.”