MARK 1.16-20: Passing alongside the Sea of Galilee, he saw Simon and Andrew the brother of Simon casting a net into the sea, for they were fishermen. (17) And Jesus said to them, “Follow me, and I will make you become fishers of men.” (18) And immediately they left their nets and followed him. (19) And going on a little farther, he saw James the son of Zebedee and John his brother, who were in their boat mending the nets. (30) And immediately he called them, and they left their father Zebedee in the boat with the hired servants and followed him. (ESV)
The Gospels of Matthew and Mark present Jesus selecting His first disciples in similar ways. The details are virtually the same and the event takes place without these gospels giving us information about Jesus’ previous interactions with the men.
A review of the book “Synopsis Quattuor Evangelorium” (meaning “Synopsis of the Four Gospels”) shows how scholars have interpreted the sequence of events in the four gospels, regarding Jesus and these disciples, Simon Peter and Andrew, James and John. This book interprets the events of Luke 5.1-8 as taking place before the above verses from the Gospel of Mark. Likewise, the Gospel of John 1.35-42 gives details of the first introductions of Andrew, and then Simon, to Jesus through John the Baptist.
The Gospel of John tells us that Andrew, and most likely also Simon, were disciples of John the Baptist, and indicates they were expectantly awaiting the revelation of the Messiah. John the Baptist was now preaching that the time of the Messiah had arrived, and these fishermen were believers in this message. Andrew met Jesus and quickly found Simon his brother and in John 1.41 said to Simon, “We have found the Messiah.” And it is at this time that Jesus gave Simon the name of “Peter”, which means “rock”.
So it is with this foundation that Jesus purposefully went to these two fishing boats, and right on the spot called them to follow Him. I believe they had already accepted Jesus as the Messiah and Lord. In Luke 5.1-11 Jesus had guided Simon Peter to a miraculous catch of fish, and Peter responded by bowing himself down before Jesus and calling Him, “Lord”.
Whether Peter was affirming with his particular use of the word “Lord” that he believed Jesus is “Adonai” or “Yahweh”, or both, I’m not sure. But he was saying that he was certain Jesus is Holy and righteous.