The following verses speak of those who have part in the FIRST resurrection which is not physical, but is to be spiritually born again of His Spirit in us. When the body of saints dies we continue to be spiritual body of Christ in heaven after death, because in life before we died we had part in the resurrection life of Christ who is the "first resurrection" of the dead. We become as the angels of God in heaven, spiritual beings without physical form. Why? Because "God is not the God of the dead, but of the living". To prove there is life after physical death for those who have part in His resurrection life, Christ says that Abraham, Isaac and Jacob though dead are of the living.
Ecclesiastes 12:7 (KJV) Then shall the dust return to the earth as it was: and the spirit shall return unto God who gave it.
1 Corinthians 15:44 (KJV) It is sown a natural body; it is raised a spiritual body. There is a natural body, and there is a spiritual body.
Matthew 22:30-32 (KJV) For in the resurrection they neither marry, nor are given in marriage, but are as the angels of God in heaven. But as touching the resurrection of the dead, have ye not read that which was spoken unto you by God, saying, I am 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.