How did God deal with the old Adam in Christ's crucifixion?
God dealt with the old Adam by crucifying him in Christ's crucifixion, placing him on the cross in His mind because God did it on our behalf. Christ died our death, fulfilling God's demand that the soul that sins must die, so the old sin nature becomes a new divine nature.
Les teaches that as the Holy Spirit enlightens understanding and regenerates the old dead spirit, a person realizes that they have died. The ego, the I, the old Adam was crucified—placed on the cross in the mind of God because God did it on our behalf. Christ died for me and you; He fulfilled God's demand that the soul that sinneth must surely die, and He died my death. When we identify with what Christ accomplished on our behalf, the Spirit regenerates our spirit, fellowship is restored, the Holy Spirit comes to dwell in the person, the old sin nature becomes a new divine nature, and this begins to affect the body and Christian walk as we grow in grace and knowledge. Les points to Romans chapter 6, where Paul makes this plain.