J B Phillips translated this verse, “Don't let the world around you squeeze you into its own mould, but let God remould 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."  By nature, our mindset wants to please the world rather than God, and glorify ourselves rather than Him.  That is why believers in Jesus are called to change their pattern of life.

However, we are creatures of habit.  Without much thinking, we continue to do things in the way we have always done them.  We are also subject to peer pressure and easily copy the people around us.  Worse than that, many believers try to be as indistinguishable as possible from the worldlings around them – trying to gain some advantage or being frightened of being rejected.

But this verse tells us to be aware of the habits which have formed our past life and decide to change, because of what Jesus has done for us (1 Peter 1:18-19).  We do so by choosing to think how to see our lives against God's standard rather than the world's.  But, the more we do so, the more the world will try to force us back into yesterday's behaviour.  That is why it is impossible without God's supernatural help to change our minds, showing us that His way is right and enabling us to prove by experience that His commands are good (Psalm 34:8-10).

Red, amber and green traffic lights have specific meanings - stop, think and get ready, and go.  This verse gives us the same sequence.  Stop allowing the world to dictate your life.  Think about what God has said in His Word, meditate on it and allow it to sink into your heart; then get ready for action.  Go: do what He says, put His Word to the test and prove that He is right (James 1:22-25).  Following Jesus is not just about spiritual thoughts and comfortable feelings.  It is an active, conscious and thought-through decision to change our lifestyle to be like Christ’s, even though the world around will not understand.  When we make that change and put it into practice, it puts us into the middle of His Will which is always the very best He could possibly arrange for us.