Hello Noel,
I think you have to remember that God exists outside of physical time which He created. God looks at the whole of physical time from infinitly before creation to infinitely beyond the end of time as a human looks at a three inch piece of yarn.
While on earth, before His death and ressurection, Jesus discusses the ressurection of Abraham, Isaac and Jacob. Jesus tells us that Abraham, Isaac and Jacob are not dead waiting to ressurect, but alive in heaven.
We know that the only way Abraham, Isaac and Jacob can be in heaven is through the blood of Jesus. We know that Jesus is the first to ressurect. One can see that Abraham, Isaac and Jacob ressurect into eternal life through the death and ressurection of Jesus to live eternally, outside of physical time, from infinitely before creation to infinitely beyond the end of physical time as God exists.
Never underestimate the Power of God.
NAB MAR 12:18
Then some Sadducees who hold there is no resurrection came to him with a question …\…12:24 Jesus said: “You are badly misled, because you fail to understand the Scriptures or the power of God. When people rise from the dead, they neither marry nor are given in marriage but live like angels in heaven. As to the raising of the dead, have you not read in the book of Moses, in the passage about the burning bush, how God told him, ‘I am the God of Abraham, the God of Isaac, the God of Jacob’? He is the God of the living not of the dead, You are very much mistaken.” **NAB LUK 20:37 **
Moses in the passage about the bush showed that the dead rise again when he called the Lord the God of Abraham, and the God of Isaac, and the God of Jacob. God is not the God of the dead but of the living. All are alive for him.