The Lord Jesus calls us to follow him, and him alone.  The Church Fathers often wrote about what this calling meant.  The following is a section of a sermon delivered by St. Jerome to his fellow monks in his monastery in Bethlehem:

'And passing near the Sea of Galilee, he saw Simon and Andrew his brother casting their nets into the sea, for they were fishermen.'  Simon was not yet Peter – for he did not yet seek Peter to him call 'Peter'.  Simon and Andrew were fishermen, since they were near the sea and were 'casting their nets into the sea.'  The Scriptures do not say that they cast their nets and caught fish.  The evangelist says that, 'he saw Simon and Andrew his brother casting their nets into the sea, for they were fishermen.'   The Gospel points out that they were casting their nets, but it does not say that they caught anything.  Before the Passion it is said that they cast their nets, still it is not written that they caught any fish.  After the Passion, however, they cast their nets caught fish.  Indeed, they caught so many that their nets broke.  'Casting their nets in the sea, for they were fishermen.'

'And Jesus said to them: Come after me and I will make you fishers of men.'  Happy the change in fishing! Jesus catches them, and they catch other fishermen.  First, they become fish so that they might be caught by Christ, and, later, they would catch others.  'And Jesus said: Come after me and I will make you fishers of men.  And at once they left their nets and followed him.  It says: And at once.'  There is no hesitation for true faith.  At once a man hears, at once he believes, at once he follows, and at once he is made a fisherman.  'And at once they left their nets.'  I myself think that leaving their nets means that they forsook the vices of the world.  'And they followed him.'  They could not follow Jesus as long as they had their nets.

'And going further a little, he saw James the son of Zebedee, and John his brother, and they were in their boat mending their nets.'  Because they were mending their nets, we know that they were rent.  They cast their nets into the sea, but because they were rent, they could not catch fish.  They were mending their nets on the sea; they were sitting on the sea; they were sitting in their boat; they were sitting with their father Zebedee; and they were mending the nets of the law.  We have said this according to the spiritual meaning of the text.  'And they were in their boat mending their nets.'  It says: 'they were in their boat.'  They were in their boat, not on the shore, and not at a firm anchorage.  They were jostled in their boat by the waves.

'And at once he called them, and they left their father Zebedee in the boat with the hired men, and they followed him.'  Now, someone may say: Their faith was rash, for what signs did they see, what majesty did they behold, that they were called, and immediately they followed him?  This shows us, reasonably, that the eyes and face of this Jesus gave off a certain divine quality, and looking attentively at his eyes, they were easily converted to him.  Otherwise, if Jesus had said to them: Follow me, they would never have followed him.  If they had followed him without reason, it would not have been faith so much as rashness.  Now, if I were sitting down and anyone at all, passing by, said to me: Come, follow me, and I did follow, would this be faith?  Why have I said all this?  Because the word of the Lord himself is effectual, and whatever he said accomplished his work.  For if, 'he spoke and they were made, he commanded and they were created,'  certainly if the same One spoke, they would have followed him.