I have been crucified with Christ. It is no longer I who live, but Christ who lives in me. And the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me. - Galatians 2:20
The Christian life is lived between opposing pressures. As children of Adam, the fall has affected every part of our existence—our body, our mind, our will, our world. We trudge through the chaos and sorrow brought on by our sin while Satan seeks to bind us in the chains of our own disordered desires. But having been born again by the Holy Spirit, we are also marked by new affections and habits towards holiness and a hatred of sin as seen in the light of God’s face.
Christians are not entirely free from the pollution of sin in this life. We all still stumble in many ways. The struggle to put sin to death is exceedingly difficult and it can be discouraging to think about how closely sin clings to us. The Apostle Paul found strength for the fight in realizing who it was that lived in him. When Christ died on the cross, he crucified our past sinful identity with him. And when he ascended up to heaven, he sent his Spirit down to bring us spiritual life so that we might repent of our sin and exercise faith in him. By faith, he indwells us with his resurrected life.
When someone is born again, Jesus makes him or her into a new creation. If Adam represents our old, sinful nature, then Jesus represents our new, righteous nature. Jesus blots out Adam’s likeness in us and stamps his own image in its place. Our union with Christ means that we are assured that we will persevere in the fight and cannot fail to be brought safely home with him at last.