In these verses, our ‘flesh’ is not the skin and muscle of our bodies, but the inner desire to please ourselves.  That self-pleasure does not accept the authority of God over us or consider any responsibility to other people.  So when we allow our ‘flesh’ to take control of our minds and body, our actions will display no regard for anybody else or God.  Indeed, we will show that we are at war with God and other people (Galatians 5:17).
 
Paul lists a variety of ways in which our ‘flesh’ wants to dictate our desires and behaviour: sexual immorality: occult activity, angry reactions, social divisiveness, and uncontrolled behaviour including drunkenness.  All of these would have been seen in the 1st century; and nothing has changed – they are still common today.  Of course, many people who had received Christ would have been those who practised such fleshly behaviour previously (1 Corinthians 6:9-11).

But now they professed to believe in Jesus Christ, they had started to change as God took hold of them (Philippians 2:12-13).  However, some so loved the old life.  They were like Lot's wife whose longing for the ‘normality of yesterday’s wickedness' destroyed her (Genesis 19:24-26).  Jesus used that story to warn the religious leaders that when He returns, all those who look back will not inherit His eternal life (Luke 17:30-37).  Paul adds his warning that unchanged behaviour meant that they had unchanged hearts: how could people who loved God also love what He hates?
 
The Christian life starts with a change of heart.  As people welcome the gospel message, they receive Christ and His transforming power.  Titus 2:11-12 says, “For the grace of God has appeared that offers salvation to all people. It teaches us to say ‘No’ to ungodliness and worldly passions, and to live self-controlled, upright and godly lives in this present age …”  In other words, if there is no change of lifestyle there is no evidence of a changed heart.  That is a spiritually dangerous place because God will not welcome those who love what He hates, and refuse to submit to Him.  So let us examine our lives and see how they reflect our hearts; then let us ask the Lord for the courage to repent and the grace to obey.