In Western Christian worship, there is a part where the faithful say "One is Holy, One is Lord, Jesus Christ, (together) with the Holy Spirit, to the glory of God the Father. Amen."
In Eastern Christianity they say "One is Holy, One is Lord, Jesus Christ, to the glory of God the Father. Amen."
Since the quote is partly scriptural (Phillipians 2:11), I can see where the Eastern version comes from (though this may not be the rigorous explanation of how it came to be in the Liturgy), but I have not yet been able to track down where/when/how/why the phrase 'with the Holy Spirit' was inserted in the Western rite.
- It was inserted to make the prayer 'more' Trinitarian. (Counterpoint: Why then would the Eastern Orthodox not include it?)
- It was inserted as a consequence of the Filioque clause in the Latin creed. I.e. if the Holy Ghost proceeds from the Son as well as from the Father, one might want to make mention of that in a sentence extolling Christ. (Counterpoint: Why would the Eastern Orthodox not include it? Well--they reject the filioque clause. In that case, what is the reason for Paul or the early Church Fathers to omit the Holy Ghost in such a sentiment, either in Scripture or in the Liturgy?)
Overall, I must ask: Is the addition of 'with the Holy Spirit' (in the above prayer) primarily of theological or cultural/traditional origin?
A more advanced answer would lay out the history of such an insertion. But I'm also happy with references I can read on my own.