How can Mary be dead if she is with the Lord. Ditto the saints? Ditto your saintly grandmother? Hebrews 12 v. 1 speaks of a cloud of witnesses about us, It strains the context to think that the preacher is only talking about the good example. True faith never dies. As for mediation, the Lord means us to be mediators, to be witnesses of the faith. When our body dies, and we encounter Jesus, face to face, do we really forget all about those who remain behind? The soul longs for the body; hence, we expect the Resurrection of the body and taking our final place in a new creation.
Robby, your claims contradict the words of Jesus.
In John 3:13, Jesus clearly says that NO ONE has ascended into heaven except the One who came from it—Jesus, Who is in heaven.
There are several places that reference the dead, which indicate that the dead are ASLEEP, as it is put, and that the dead will be called to life on the LAST DAY, the Day of the Lord, when the dead will be judged.
You are misinterpreting Hebrews 12:1. It does not refer to dead people actually floating around us. You must look back in the preceding text to understand the context of that verse, which has to do with faith and perseverance.
Nowhere in the Bible does it say that when we die, we immediately encounter the Lord. Instead, it says we sleep until the Day of the Lord.