One of the problems of being with people for long periods of time is that you start to grow like them.  It is said that dog owners can end up looking like their pets, and certainly students take on the characteristics of their tutors.  Children can adopt the behaviour of the heroes of their video games.  Adults can act out the roles of film or soap idols.  Employees too are unwitting shadows of their bosses or other workmates.    

In this passage, the word 'Gentiles' is used for people who have no understanding of God's truth or how to relate to His Lordship.  Therefore, they are at risk of taking on the characteristics of their spiritual master, Satan (John 8:44-47).  Such people, however nice they may appear, cannot see the light of Christ; they are ignorant of truth and live lives in spiritual darkness, separate from God.  That lifestyle is futile for it has no good end-point.   

Hard heartedness is not just a bullish business nose: it is the automatic resistance of sinful human nature to the authority and rule of God in their lives.  It is a spiritual callus which protects their conscience from feeling the pain of wrong living, and so there is little to restrain them from indulging in any sort of impurity.  This refers to sexual impurity of course, but also to anything that makes us unclean in the sight of God: dishonest finance, lies of convenience, 'sickness' due to laziness or a late night, arrogance to clients and jealousy of another's promotion.  The problem does not just stay there; the spiritual callus is so insensitive to truth that the unsatisfied soul has a hunger to go on being even more impure.

The Apostle Paul says that Christians should be radically different.  He says that he has the Lord's authority to insist on it! That way of life which is all around us, and wants to mould us into the same shape, must be resisted at all costs.  JB Phillips' translation of Romans 12:2 says, "Do not let the world squeeze you into its mould, but instead let yourself be transformed by the renewing of your mind".  

This is the biggest daily challenge at work.  James describes God’s Word as a mirror showing us what we look like to God (James 1:22-25).  We need to compare ourselves with Jesus first, rather than imitating the world around us (Hebrews 12:1-3).    As our minds and hearts become saturated with the Word of life, filling our minds with the things that please God (Philippians 4:8-9), we will model our lives on Him, and choose to deny ourselves the luxury of flirting with the devil (Ephesians 4:27).  We will then have a radically different life to offer to our work colleagues (Philippians 2:14-16).