Once God had commissioned Jesus (3:17), the devil had tested him (4:3-11), the forerunner had completed his mission (4:12) and Jesus had settled in Capernaum (4:12-16), he was ready to begin his public ministry (from that time on, 4:17). Matthew opens this section with a summary of Jesus' message (v. 17). As this message summarizes Jesus' proclamation of God's authority, so verses 18-22 demonstrate people's proper response to God's rule; verses 23-25 demonstrate God's rule over sickness and demons; and chapters 5-7 flesh out the nature of the ethic of repentance one must live to be prepared in advance for the kingdom.

For Matthew, the message for both Galilean Jews (10:5-7) and eventually Gentiles (28:18-19) is the same as John the Baptist's (3:2) and that of Jesus: Get your lives in order, for God's kingdom is approaching (4:17). Only those who submit to God's reign in advance (as in 4:18-22) will be ready when he comes to rule the whole world. Just as Jesus' message concurred with that of John, so the message of Jesus' followers must accord with that of Jesus. We must proclaim the imminence of the kingdom (10:7; compare 28:18), demonstrate God's rule over sickness and demons (10:8), and pass on our Master's teachings (28:19).

In 4:18-22 the One whom the Father called now calls others who will advance his mission. Jesus' call to leave profession and family was radical, the sort of demand that only the most radical teacher would make. This text provides us several examples of servant-leadership and radical discipleship.