By the Lake of Gennesaret, the crowd presses around Jesus to hear the word of God. He gets into Simon's boat and teaches from it. When he finishes, he tells Simon to put out into deep water and let down the nets. Simon, who has fished all night with nothing, obeys, and the net fills so full that it nearly breaks and the boats begin to sink. Simon falls at Jesus' feet and asks him to leave because he is a sinful man. Jesus tells him not to fear; from now on he will catch people. Simon, James and John leave everything and follow him.
In one town, a man full of leprosy begs Jesus to make him clean. Jesus touches him and heals him, and tells him to show himself to the priest. Later, while Jesus is teaching in a house full of Pharisees and teachers of the law, some men climb onto the roof and lower a paralytic on a stretcher. Jesus sees their faith and tells the man his sins are forgiven. The scribes are scandalized because only God forgives sins. To show that the Son of Man has authority to forgive, Jesus orders the man to get up, and he goes home glorifying God.
Jesus calls Levi, a tax collector, who leaves everything and follows him and gives a great banquet with other tax collectors and sinners. The Pharisees complain, and Jesus answers that the healthy do not need a doctor but the sick do. They then ask why his disciples do not fast; he speaks of the bridegroom being present and of new wineskins for new wine.