Well that is actually stated in the Bible: And hath raised us up together, and made us sit together in heavenly places in Christ Jesus (Eph 2:6)...we are already sitting in heavenly places...
Since all the children of God are in the Body of Christ, and since Christ is seated at the right hand of the Father in Heaven (heavenly places) it follows that in the eyes of God and Christ we are already seated with Him in Heaven. This is a spiritual reality.