From Wikipedia, the free encyclopedia     https://en.wikipedia.org/wiki/Doxology

A doxology (Ancient Greek: δοξολογία doxologia, from δόξα, doxa 'glory' and -λογία, -logia 'saying') is a short hymn of praises to God in various forms of Christian worship, often added to the end of canticles, psalms, and hymns. The tradition derives from a similar practice in the Jewish synagogue, where some version of the Kaddish serves to terminate each section of the service. 

Among Christian traditions a doxology is typically an expression of praise sung to the Holy Trinity: the Father, the Son, and the Holy Spirit. It is common in high hymns for the final stanza to take the form of a doxology. Doxologies occur in the Eucharistic prayers, the Liturgy of the Hours, hymns, and various Catholic devotions such as novenas and the Rosary. 

The Gloria in excelsis Deo, also called the Greater Doxology, is a hymn beginning with the words that the angels sang when the birth of Christ was announced to shepherds in Luke 2:14. Other verses were added very early, forming a doxology. 

Gloire a Dieu au plus haut des cieux

The Gloria Patri, so named for its Latin incipit, is commonly used as a doxology in many Christian traditions, including the Roman Catholics, Old Catholics, Independent Catholics, Orthodox, Lutherans, Anglicans, Presbyterians, Methodists, Disciples of Christ, Reformed Baptists and United Protestants. It is called the "Lesser Doxology", thus distinguished from the "Great Doxology" (Gloria in Excelsis Deo), and is often called simply "the doxology". As well as praising God, it was regarded as a short declaration of faith in the equality of the three Persons of the Holy Trinity. 

In the Catholic Mass a prose doxology concludes the eucharistic prayer, preceding the Our Father. It is typically sung by the presiding priest along with any concelebrating priests. The Latin text reads:

Per ipsum, et cum ipso, et in ipso, est tibi Deo Patri omnipotenti in unitate Spiritus Sancti, omnis honor et gloria per omnia saecula saeculorum. Amen. (1. Through him, with him, in him, in the unity of the Holy Spirit, all glory and honour is yours, almighty Father, forever and ever Amen. and 2. Through him, and with him, and in him, O God, almighty Father, in the unity of the Holy Spirit, all glory and honour are yours, forever and ever. Amen.)

The equivalent passage in the Book of Common Prayer (1549) of the Church of England reads:

By whom and with whom, in the unity of the Holy Ghost, all honour and glory be unto thee, O Father almighty, world without end. Amen

Another familiar doxology is the one often added at the end of the Lord's Prayer: "For thine is the kingdom, and the power, and the glory, forever and ever, Amen." This is found in manuscripts representative of the Byzantine text of Matthew 6:13, but not in the manuscripts considered by Catholics to be the most reliable. According to Scrivener's "Supplement to the Authorized English version of the New Testament", it is omitted by eight out of 500 or so manuscripts. Some scholars do not consider it part of the original text of Matthew, and modern translations do not include it, mentioning it only in footnotes. Since 1970, the doxology, in the form "For the kingdom, the power, and the glory are yours, now and forever", is used in the Roman Rite of the Mass, after the Embolism. The Catholic Encyclopedia (1914) claims that this doxology "appears in the Greek textus receptus and has been adopted in the later editions of the Book of Common Prayer, [and] is undoubtedly an interpolation." In fact, the Lord's Prayer doxology is often left away by Catholics, such as in the Liturgy of the Hours, or when, which is quite often outside Mass, a Hail Mary follows immediately (e. g. in the Rosary where the Gloria Patri serves as a doxology).

According to the Catechism of the Catholic Church, this doxology takes up

the first three petitions to our Father: the glorification of his name, the coming of his reign, and the power of his saving will. But these prayers are now proclaimed as adoration and thanksgiving, as in the liturgy of heaven. The ruler of this world has mendaciously attributed to himself the three titles of kingship, power, and glory. Christ, the Lord, restores them to his Father and our Father, until he hands over the kingdom to him when the mystery of salvation will be brought to its completion and God will be all in all

The Didache - The Complete Text

Listen & Read it at the same time!

The Didache 

1 There Are Two Ways

2 The Second Commandment

3 My Child, Flee Evil

3:9 Don't exalt yourself or open your heart to overconfidence. Don't be on intimate terms with mighty people, but with just and lowly ones.

3:10 Accept whatever happens to you as a blessing, knowing that nothing comes to pass apart from God.

4 My Child, Remember

This is the way of life!

5 The Way of Death

6 See That No One Leads You Astray

7 Concerning Baptism

8 Your Fasts and prayers

9 Concerning the Eucharist

10 After the Eucharist

Hosanna to the Son of David! If anyone is holy, let him come; if anyone is not holy, let him repent. Maranatha! Amen.

11 Welcome the Teacher

12 Welcome Anyone Coming in the Name of the Lord

13 Every Genuine prophet

14 On the Lord's Day

15 Appoint Bishops for Yourselves

16 Watch Over Your Life

Video of the Didache is a third party post on YouTube