First, God is the God of the living. As Matthew 22:32 says: “ ‘I am the God of Abraham, and the God of Isaac, and the God of Jacob’? He is not God of the dead, but of the living.’” Our souls never die or “sleep” but after death we are judged. Those that enter Heaven live in joy forever. These are saints. Also, when Moses and Elijah appeared at Jesus’ transfiguration, were they not alive in God or where those simply manifestations that Jesus called forth? It’s clear they were alive.
After a whole chapter describing the ancient people of faith in Hebrews 11, Hebrews 12:1 goes on to say, “Since we are surrounded by such a great cloud of witnesses...” What possible interpretation can anyone give but that those who have died are aware of us and are watching us? The saints in Heaven continuously intercede for mankind (CCC 956).
That is not being argued. What is being argued is that the souls who have departed from this earthly existence are referred to as "dead", and are not to be attempted to be contacted on any level, as it is prohibited by God in the Scriptures.
1 Corinthians 15:12 Now if Christ is preached that He has been raised from the dead, how do some among you say that there is no resurrection of the dead?
Departed souls are referred to as "the dead".
Because the souls of departed saints are alive in eternity is not license to break the commandment of God against attempts to contact the souls of those who have departed this space/time continuum.
THAT is very interesting because I recently had a conversation with Kosta and Kolo about this, but in the context of where the OT righteous went immediately after they died. My contention was that they went straight to Heaven, and offered the evidence of the Transfiguration. IOW, I agree with you that they WERE real and alive. In order to support the Orthodox position that no one went to Heaven before the crucifixion (anyone correct me if I'm wrong), I remember the response being that Moses and Elijah possibly were indeed manifestations, and not real or alive. So, my question is: does Catholicism support that the OT righteous went directly to Heaven upon death, and that Jesus' sacrifice retroactively applied to them at the time of their deaths?