Christ's death can be experienced by us only through Christ's resurrection, and Christ's resurrection can be real to us only by the bountiful supply of the Spirit of Jesus Christ. Jesus Christ has become the life-giving Spirit, and He is within us. When we turn to our spirit, we meet Christ as the life-giving Spirit, who is the very reality of Christ's resurrection. It is by this Spirit that we experience Christ's resurrection. To experience Christ's resurrection is to contact the life-giving Spirit.
In order to apply this we have to remain in our spirit all the time to meet Christ as the Spirit, who is the reality of His resurrection.