The Christian life inevitably includes a call away from the past.  Peter and Andrew were cleaning their nets (Mark 1:16-18); James and John were preparing their nets, but Jesus called all four to leave their nets and follow Him.  The call to follow was so authoritative that they obeyed.  It made sense to their hearts even though it separated them from the tools of their trade, their primary family loyalty and their financial security.  What the Lord Jesus injected into the lakeside beach was a commission to fulfil their 'design specification' - by serving and glorifying the Lord through doing whatever He wanted them to do (2 Corinthians 5:17).  That is the highest purpose of mankind.

Jesus calls purposefully.  He chose His walking route that day; knew where the men were working, and all about them (Job 23:10).  He did not spend a long time in small-talk, as is the Eastern custom, but immediately called them to leave their nets without any delay.  His call was not just an interesting invitation but a powerful command.  God the Son had chosen them, and their hearts responded: not with a discussion or even a word, as far as we know, but by leaving their familiar and legitimate lifestyle to follow Jesus (John 15:16).  Their father, who had hired other workers to handle the growing business was now without his heirs – who were also his pension fund.  But the call of Jesus took precedence over everybody and everything (Luke 5:11).  

Is this an instruction to the modern Christian to leave home, the football club, the routines of working life and the responsibilities towards our families?  Probably not, but it is a healthy reminder that whilst the purpose of work is to provide for our own and the family's needs - it is not the purpose of life!  For many people, the need to earn money and the sheer satisfaction of successful business or professional life distorts their life's purpose.  In the Lord's eyes, we are not significant or secure by what we do, but by why we do it: whether it is the line of His calling (2 Corinthians 5:9).  That starts by humbly accepting Christ's authority over us, being cleansed of our sin, forgiven, and learning to follow Him in the power of the Holy Spirit (Ephesians 3:16-21).

We can fill our life with activity but fail to achieve our divine purpose, unless we obey the Lord's instructions.  If we refuse to walk into the future shaped by God's call, we will stay in a future constructed out of our own background with all the faults we have inherited and learned along the way (Matthew 19:21-22).  It may be that the Lord tells us to continue to do the same things as before, but His call will reveal a fresh purpose; we will know we are doing it for Him (1 Thessalonians 4:11-12).  For others, the voice of God will lead us into a new adventure with Him and it could be a totally different lifestyle altogether (Mark 10:29-31).  For all who obediently respond to Jesus we know that we are living to work for the King and not for ourselves (2 Corinthians 5:15).