Mark 1:12-20 ESV
(12) The Spirit immediately drove him out into the wilderness.
(13) And he was in the wilderness forty days, being tempted by Satan. And he was with the wild animals, and the angels were ministering to him.
(14) Now after John was arrested, Jesus came into Galilee, proclaiming the gospel of God,
(15) and saying, "The time is fulfilled, and the kingdom of God is at hand; repent and believe in the gospel."
(16) 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.
(20) And immediately he called them, and they left their father Zebedee in the boat with the hired servants and followed him.
Verses 12 and 13 contain all that Mark has to say about Christ's temptation in the wilderness. I'm not sure why Mark doesn't go into the detail Matthew does in Matt. 4 -- I'd speculate that it was because he had read Matthew and didn't want to repeat information, but that theory really doesn't hold water -- there are other things that Matthew and Mark treat almost identically. Mark mentions this early stage of Christ's ministry simply to set the stage -- he spends a lot more time talking about Jesus' actual ministry.
Verse 14 kicks off the opening stage of Jesus' ministry in Galilee with the calling of the disciples. Simon, Andrew, James, and John are the first four. Andrew (according to John 1:35-40) was a follower of John the Baptist, and was prepared for the coming of the Messiah.
Andrew is one of the more underrated disciples. We don't read much about him in the Bible, he wasn't one of the "big three" (Peter, James, and John). But we read in John 1 that after he met Christ, he ran to tell Simon (Peter) about Him. The very first evangelist -- and his convert became one of the leaders of the early Church.
James and John are interesting case. They are aparantly wealthy, because their father has servants to help on the boat. Not just fishermen -- these two owned their own business, and so were probably highly educated. That will come back to haunt them later on, when they start competing for the position of Christ's "right-hand man" when His kingdom is established.
The thing to notice is that all four of these men had important jobs that they were doing. They were responsible for feeding not only their families, but the families living around them. They provided food each day for the community. And when Christ called them, they dropped what they were doing to follow Him. How often do we put off doing what Christ wants us to do because we can't afford it, or we're too busy, or something like that. I've used those excuses before -- God has a way of making us unbusy when He needs us.