“Then He said to them, “Follow Me and I will make you fishers of men.”” Matthew 4:19 (NKJV)
In the previous verse Simon (Peter) and his brother Andrew are called fishermen; Jesus’ call to them does not change what they do so much as it changes who they are and their focus in life. They will continue in their life’s work except that now their quarry is the souls of men rather than schools of fish. Although their work is similar in some ways, and their dedication will become legendary, they are now known as Apostles rather than fishermen.
All of us have at one time or another been defined by what we do, by something that we were good at like Peter and Andrew; this activity may be good or bad but it is seldom the identity that God has in mind for us. When God calls us (and He calls every believer), He may or may not choose to use our former vocation as a basis for our new life. In the case of Peter and Andrew Jesus turned their zeal for fishing into compassion for souls.
When we have experienced the call of God we can’t afford to let our worldly activities define us; to be effective witnesses for Him we must be known by our relationship with Him and not by what we once did, or even by those secular activities which we continue to be involved in. The two Apostles identities were superseded by their new vocation as God’s sent ones. Although they may still fish, no longer are they known by their former work; they are now transformed into men who will establish Christ’s church throughout their world as their relationship with Jesus gives new meaning to life.
As with the Apostles, Christianity is not simply something we do, it must be who we are as reflected by our relationship with God through Jesus Christ. Does it mean that we will not make mistakes, or not sin? Not necessarily, it is God’s perfect will is that we love and trust Him in all things and live our lives accordingly; His permissive will allows for our humanness and His grace covers our sins if we repent. It was this mind set that allowed and even compelled them to be all that they could for their Savior, and to be known by their faith and devotion to Him.