A teacher or master has to train his apprentices or disciples, and part of that is doing what they are taught. You cannot learn any profession, trade, or craft out of a textbook. You need to do it under guidance. Initially see it, then do it with guidance, then do it by yourself.
Christ was training his disciples.
5 These twelve Jesus sent out, instructing them, “Go nowhere among the Gentiles and enter no town of the Samaritans, 6 but go rather to the lost sheep of the house of Israel. 7 And proclaim as you go, saying, ‘The kingdom of heaven is at hand.’ 8 Heal the sick, raise the dead, cleanse lepers, cast out demons. You received without paying; give without pay. 9 Acquire no gold nor silver nor copper for your belts, 10 no bag for your journey, nor two tunics nor sandals nor a staff, for the labourer deserves his food. 11 And whatever town or village you enter, find out who is worthy in it and stay there until you depart. 12 As you enter the house, greet it. 13 And if the house is worthy, let your peace come upon it, but if it is not worthy, let your peace return to you. 14 And if anyone will not receive you or listen to your words, shake off the dust from your feet when you leave that house or town. 15 Truly, I say to you, it will be more bearable on the day of judgement for the land of Sodom and Gomorrah than for that town.
But Christ was also winnowing communities. There were those who knew they were lost and welcomed him. There were those who considered themselves guides to ghe gentiles and despised the Samaritans, and saw no need for salvation.
We still have such.
And those communities will face a harsher judgement than those who live in towns that are bywords for evil and corruption.
If Christ told his disciples to go and find the lost, he continues to do it now.