This is an early instruction for Christian communities dated from about 100AD. There are a couple of main things to learn from it.
1. Christianity was largely about behaving yourself properly within a community.
2. The seemingly cuckish advice in the New Testament was meant to be exercised within good communities where assholes taking advantage of the situation were to be expelled, not among randos in modern scum society.
https://reformedwiki.com/read-didache-roberts