For if we have been united with him in a death like his, we shall certainly be united with him in a resurrection like his.  We know that our old self was crucified with him in order that the body of sin might be brought to nothing, so that we would no longer be enslaved to sin. (ESV)
One of the greatest stumbling blocks for people in coming to faith in Jesus Christ is their belief in their own basic goodness. Men want to think that they are not that bad. They certainly are not as bad as those who populate the local jail. They are better than their neighbor and somehow that qualifies them for God's approval.
As you look closely at the two verses we have before us today one thing becomes very clear. Our natural self was so sinful that we not only had to have it done away with, it needed to be crucified with Jesus Christ. Crucifixion was not just any death. It was the most gruesome, painful, humiliating way for any man to die.
Our sinful nature needed to be killed in the most demonstrative way possible. Our sin is that repulsive to God the Father. We do a great disservice to the truth when we act as if there is any goodness in our own nature. We are not saved because we are so clever and an act of our will gave us right relationship with God.
We identify with the death of Christ. That means that we acknowledge the very sinfulness of our own nature, agreeing that our sin made us deserving of death. Thankfully, Christ's work on the cross not only puts to death our old self, but it gives us the promise of a resurrection like the Savior's. We have a new life and an eternal future. All of this is possible because of the cross.
How good do you think you are? Good enough to deserve crucifixion? Identify with Christ and the cross. Be thankful that your sinful nature can be put to death and you can be raised to new life by faith in the Son of God.