Also see definition of "Doxology" in Word Study
Study Dictionary
Doxology
DOXOLOGY [ISBE]
DOXOLOGY - dok-sol'-o-ji (doxologia, "a praising," "giving glory"): A hymn or liturgical formula expressive of praise to God, as the Gloria in Excelsis (an expansion of Lk 2:14), sometimes called the Greater Doxology, and the Gloria Patri ("Glory be to the Father, and to the Son, and to the Holy Ghost, world without end, Amen") also known as the Lesser Doxology.The clause, "as it was in the beginning, is now, and ever shall be," was probably added to the original simple formula to emphasize the church's dissent from the Arian conception of Christ.
The term is applied in particular to the concluding paragraph of the Lord's Prayer (Mt 6:13 margin, "For thine is the kingdom," etc.; compare 1 Ch 29:11, and see LORD'S PRAYER).
To the same general class belong Ps 41:13; 72:18 f; 89:52; Rom 16:27; Eph 2:20; 1 Tim 1:17; Jude 1:25; Rev 5:13 f; 19:1-3, and the modern stanza beginning "Praise God, from whom all blessings flow."
M. O. Evans
Also see definition of "Doxology" in Word Study
