It’s not like it is a bad thing, and it is very ancient. So ancient in fact, that churches which have been separated from each other since the Council of Chalcedon use it in the same way in their Divine Liturgies, and the Catholic churches following the same liturgies also use it.
As YADA explains, it is present in the Didache, a document composed in the second century as a catechetical tool. The use of the Doxology is liturgical, which means it is the received teaching of the church. The doxology is so important, being a form of Creed, that is is repeated several times in a typical eastern Christian liturgy.
More than likely the Textus Receptus of Erasmus was derived from a much earlier Orthodox manuscript that had a marginal gloss which included this Doxology as a pious exclamation, and somehow in later copies it was written right into the basic textual lines by mistake. It was not invented by some copyist as a comment or ejaculative prayer, it was an already existing creedal formula very familiar to millions of Christian from their liturgical practices.
So the reason Protestants will use it is not the same reason Orthodox will use it. In other words, all over the east this doxology appeared IN THE LITURGY of the ancient church, but apparently not in the version of western liturgy (the Mass) which would eventually come to predominate in western Europe.
The Protestants therefore, did not inherit this form from their Roman Catholic predecessors, they found it in their Bible, wittingly or not actually borrowing an Eastern Catholic church practice.
Now the first Protestant leaders were almost all trained as priests in the Roman Catholic church, and they were no dummies, quite a few of them were probably familiar with the texts of the “ancient” eastern liturgies. But I don’t know that they would have put the Doxology into their Prayer service on that basis. They might have suspected the Latin church of removing the doxology at some point. In fact the liturgy as used in Rome may have never had it, although some of the suppressed liturgies (Celtic, Mozarabic, North African, Gallic, Ambrosian) may have used it.
Divine Liturgy of
Saint John Chrysostom [Greek Orthodox, also Russian etc.]:
**Priest:**And make us worthy, Master, with confidence and without fear of condemnation, to dare call You, the heavenly God, Father, and to say:
**People:**
Our Father, who art in heaven,
- hallowed be Thy name.*
- Thy kingdom come;*
- Thy will be done,*
- on earth as it is in heaven.*
- Give us this day our daily bread,*
- and forgive us our trespasses*
- as we forgive those who trespass against us,*
- and lead us not into temptation,*
- but deliver us from evil.*
**Priest:**For Yours is the kingdom and the power and the glory of the Father and the Son and the Holy Spirit, now and forever and to the ages of ages.
Soorp Badarak [of the non-Chalcedonian] Armenian Orthodox:
PRIEST:And grant us to open our mouths with cry of bold voice, to call upon Thee O Heavenly Father, to sing and say…
CHOIR:
Our Father, which art in heaven, hallowed be Thy name; Thy kingdom come; Thy will be done, on earth as it is in heaven. Give us this day our daily bread; and forgive us our debts, as we forgive our debtors; and lead us not into temptation, but deliver us from evil.
PRIEST:For Thine is the kingdom and the power and glory, unto the ages. Amen. + Peace unto all.
The appearance of the Doxology in the later Latin Rite Mass (the Missa Normativa) has probably nothing to do with the presence of Protestant observers at Vatican II, regardless of what some people try to claim.
It much more likely was a result of the influence of many Eastern Catholic participants in the Vatican Council, who (probably to their own surprise) for the first time seem to have actually been listened to in earnest, as if what they had to say is important.
I know that the Fathers of that Council had the opportunity to participate in the many non-Roman Rite liturgies of the church and been exposed to the full length and breadth of Apostolic liturgical practices, I have a recordings of those liturgies released as a commemorative set on vinyl.
Michael