Because the preaching is of primary importance, Jesus emphasizes the need for his followers to be discreet so as to remain free to carry out this work. He says: “When they persecute you in one city, flee to another; for truly I say to you, you will by no means complete the circuit of the cities of Israel until the Son of man arrives.”​—Matthew 10:23.

Clearly, Jesus has the future in mind in saying these things to the apostles. Consider his statement that his disciples will not complete their circuit of preaching “until the Son of man arrives.” Jesus is indicating that his disciples will not complete the preaching about God’s Kingdom before the glorified King Jesus Christ arrives as God’s judge.