Paul has been building a foundation for the the Colossians for how to live in the spirit, now he gets practical. Paul gives instruction to the church for how to take this truth in to the two most important spheres of our live: our Family and our work.  Paul intention here is to show us how to create a culture where the kingdom of heaven reigns making space for God to work in our and then empowering us to take that truth into the world, as salt to a dying world.  Colossians 3:18-4:6