Anonymous 
The Lord’s Teaching Through the Twelve Apostles to the Nations (The Didache) [EPUB ebook] 

The Didache  also known as
The Lord’s Teaching Through the Twelve Apostles to the Nations is a brief anonymous early Christian treatise written in Koine Greek, dated by modern scholars to the first or (less commonly) second century AD. 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. The opening chapters describe the virtuous Way of Life and the wicked Way of Death. The Lord’s Prayer is included in full. Baptism is by immersion, or by affusion if immersion is not practical. Fasting is ordered for Wednesdays and Fridays. Two primitive Eucharistic prayers are given. Church organization was at an early stage of development. Itinerant apostles and prophets are important, serving as ’chief priests’ and possibly celebrating the Eucharist. Meanwhile, local bishops and deacons also have authority and seem to be taking the place of the itinerant ministry.
Translated by 
Charles Hoole .