Didache
The Didache (; Ancient Greek: Διδαχή, romanized: Didaché, lit. 'Teaching'), also known as The Lord's Teaching Through the Twelve Apostles to the Nations (Διδαχὴ Κυρίου διὰ τῶν δώδεκα ἀποστόλων τοῖς ἔθνεσιν, Didachḕ Kyríou dià tō̂n dṓdeka apostólōn toîs éthnesin), is a brief anonymous early Christian treatise (ancient church order) written in Koine Greek, dated by modern scholars to the first or (less commonly) second century AD. The first line of this treatise is: "The teaching of the Lord to the Gentiles (or Nations) by the twelve apostles". The text, parts of which constitute the oldest extant written catechism, has three main sections dealing with Christian ethics, rituals such as baptism and Eucharist, and Church organization.