Letters written under difficult circumstances are writings that reveal what is most important to the writer. Paul's prison letters are no exception. They show the depth of his spiritual understanding. In particular, he reveals his deep appreciation of who Jesus Christ is in the opening chapter of Ephesians and in the Christ-hymns of Philippians 2 and Colossians 1. As is customary with Paul, we read first about the doctrinal foundations of our faith. Once the doctrinal foundation has been taught we move to the practical outworking of the truths. This truth is not so that we have a head knowledge of the faith, but is something intended to change our behaviour. In Ephesians Paul discusses our position in Christ, that we are seated in heavenly places in Him as the basis for our Christian walk and warfare. In Philippians two words or word groups are prominent: joy and mind. Christians are to have the same mind as Christ, earnestly following His example. It is for good reason that Paul says "Let this mind be in you which was also in Christ Jesus". Then we can rejoice in the Lord. Colossians teaches that following a set of rules is not the way to follow Christ while the letter to Philemon is a plea on behalf of a converted slave.