The Didache or The Teaching of the Twelve Apostles (Didachē means "Teaching") is a brief early Christian

Early Christianity

Early Christianity is generally considered as Christianity before 325. The New Testament's Book of Acts and Epistle to the Galatians records that the first Christian community was centered in Jerusalem and its leaders included James, Peter and John....

 treatise

Treatise

A treatise is a formal and systematic written discourse on some subject, generally longer and treating it in greater depth than an essay, and more concerned with investigating or exposing the principles of the subject.-Noteworthy treatises:...

, dated by most scholars to the late first

Christianity in the 1st century

The earliest followers of Jesus composed an apocalyptic, Jewish sect, which historians refer to as Jewish Christianity. The Apostles and others following the Great Commission's decree to spread the teachings of Jesus to "all nations," had great success spreading the religion to gentiles. Peter,...

 or early 2nd century

Christianity in the 2nd century

The 2nd century of Christianity was largely the time of the Apostolic Fathers who were the students of the apostles of Jesus, though there is some overlap as John the Apostle may have survived into the 2nd century and the early Apostolic Father Clement of Rome is said to have died at the end of the...

. The first line of this treatise is "Teaching of the Lord to the Gentiles (or Nations) by the Twelve Apostles" (Διδαχὴ κυρίου διὰ τῶν δώδεκα ἀποστόλων τοῖς ἔθνεσιν).

The text, parts of which constitute the oldest surviving written catechism

Catechism

A catechism , i.e. to indoctrinate) is a summary or exposition of doctrine, traditionally used in Christian religious teaching from New Testament times to the present...

, has three main sections dealing with Christian ethics, rituals such as baptism

Baptism

In Christianity, baptism is for the majority the rite of admission , almost invariably with the use of water, into the Christian Church generally and also membership of a particular church tradition...

 and Eucharist

Eucharist

The Eucharist , also called Holy Communion, the Sacrament of the Altar, the Blessed Sacrament, the Lord's Supper, and other names, is a Christian sacrament or ordinance...

, and Church organization.