Persecution might make us run away, and/or make us cry out for the return of Christ.  Both may be right and echo the story of the Early Church spreading out with the gospel because of persecution (Acts 11:19).  But Jesus said, when others hate us because of Him, that is not the signal to retreat from the gospel, but to advance!  So, Jesus' instruction: "be on your guard", was not advice about our personal protection.  It echoes Mark 13:5, "Watch out that no-one deceives you".  A greater danger than death was that the gospel might be distorted (Galatians 1:6-9).  The disciples needed to be alert and prepared, so that they would never step back from Jesus being Saviour and Lord.  They needed to respond well when the attacks came (1 Peter 3:15).  Jesus knew all about the future opposition; in fact, He would use it - it was all part of the gospel strategy.

Through persecution, the believers would have to explain their beliefs to the highest religious and civil authorities.  The 'Jesus phenomenon' was never designed to be a private and hidden piety - but to be broadcast.  So, the disciples were not to hide their faith, and not to worry about how they would defend themselves. The Holy Spirit would be directing operations - so that through human hostility, the peace of God might be presented to kings and whole nations (Acts 26:24-29).

It is the united plan of the Father, Son and Holy Spirit that the gospel must be preached to all ethnic groups (Matthew 28:18-20) before the end comes.  He wants everybody to be saved through knowing the truth (1 Timothy 2:4): He does not want anybody to perish (2 Peter 3:9).  Persecution is one of God's missionary mechanisms.  Therefore, Jesus said, "Do not worry".  He has it all under control.  He knows the way we take and He will refine us so that we may be sharper instruments in His hand (Isaiah 49:2).

Nobody likes disapproval, antagonism or hatred.  That is why we need to be on our guard (against ourselves!).  Human reactions will urge us to hide, fight, worry and even lie about our confidence in Christ.  But when we understand God's strategy, and are working with the Holy Spirit (instead of resisting His way), then we can be less precious about ourselves, and more confident that God knows what He is doing.  The purpose is that we will speak about the grace of Jesus Christ - and others will be saved!