By nature, we tend to become like the people around us.  It is as though they set the shape into which we pour our lives.  Moulding technology is commonly used for reproducing anything from car parts to toys, in metal or plastic, and even chocolate.  Once the mould has been designed, whatever goes into it will come out with the same shape and characteristics.  The same is true with the 'factory' of our hearts.  Our desires provide the mould which produces behaviour (James 1:14-15).  Sinful desires lead to sin.

Before we knew Christ, we simply conformed to the society around us.  We did not know any better.  But when we became children of God, He placed His truth in our hearts (Jeremiah 31:33) to displace ignorant lies.  He gave us new desires, and a new heart (Ezekiel 36:26) that is capable of pleasing Him.  But we are not robots in a production process, automatically filled with holiness: we have the responsibility to stop pouring ourselves into the old sinful mould, and to choose to obey the Lord (Ephesians 4:23-24).

JB Phillips translation of Romans 12:1-2 is helpful, ‘With eyes wide open to the mercies of God, I beg you, my brothers, as an act of intelligent worship, to give him your bodies, as a living sacrifice, consecrated to him and acceptable by him. Don’t let the world around you squeeze you into its own mould, but let God re-mould your minds from within, so that you may prove in practice that the plan of God for you is good, meets all his demands and moves towards the goal of true maturity.’  

We who have God’s Word are not ignorant; we are responsible to think-through, decide and control ourselves in a lifestyle which pleases the Lord – because we love Him.  As His Word sets the pattern for our lives, our desires, choices and character should become shaped by what we know will honour Him.  That happens through our daily decisions in the workplace and at home.  God's heart for integrity, merciful justice and humility (Micah 6:8) should be expressed in time sheets, expenses claims and appraisal forms.  Dishonest trading and exploitation do not come from God, neither do slander or rage (Ephesians 4:31).  Peter urges us to be active in rejecting those old lifestyles and choose to be obedient children of God.