In this, the last of three practical lessons about discipleship for the trainee apostles, Jesus taught them to understand what lay behind delaying and evading tactics from would-be disciples.  Saying farewell to family seems to be only courteous, a way to let them know that an exciting new path of life has opened up.  But in Jesus' day and culture, 'goodbye' would take at least three days and possibly a week as relatives gathered.  By that time, Jesus would have moved on and the opportunity would have gone.  An apparent willingness becomes hard-heartedness when we fail to say ‘Yes’ today (Hebrews 3:12-15).

Jesus had just spoken about how to choose between the competing demands of family and faith (Luke 9:59-60).  It was not that He wanted anybody to dishonour their parents or fail to provide for their children, but when there was a conflict of whose call gets priority God has the right to decide.  In this exchange, Jesus identifies when a good desire to follow Him is choked by other relationships.  It is a strong rebuke.  Such people are ‘not fit for the kingdom of God’.  

The apostles were going to encounter many who were attracted by the gospel truth but were not wholehearted because they loved their present way of life too much.  The temptation to look back (like Lot's wife in Genesis 19:24-26) is rooted in our sinful nature.  Jesus called for a distinct break from the past and condemned the duplicity of trying to look in two directions at the same time: such a person is not fit to be a disciple.  And it seems that Jesus is making clear that discipleship is as hard a lifestyle as that of the ploughman.  When ploughing a furrow, the only way to ensure that you plough straight and cover the ground properly is to fix your eyes on a point ahead, at the end of the field.  For Jesus: that point was the cross.  

For us: that focus must rest on Jesus alone.  He will return in glory (1 Peter 1:3-9).  His ‘appearing’ will mark the completion of His saving work in us, as well as the judgement of the world which has rebelled.  Those two end-points are completely opposite to each other; so to attempt to live in both directions will produce dangerous personal instability (James 1:8) and must be repented of before it is too late (James 4:8).  The workplace may tempt us to look back; family, friends and colleagues may discourage us from being whole-hearted for Jesus; but He has set the example and we must follow -  as it says in Hebrews 12:2-3: "… fixing our eyes on Jesus, the pioneer and perfecter of faith. For the joy that was set before him he endured the cross, scorning its shame, and sat down at the right hand of the throne of God. Consider him who endured such opposition from sinners, so that you will not grow weary and lose heart."