+O Holy God,
O Holy Mighty One,
O Holy Immortal One,
Have mercy on us.

+O Holy God,
O Holy Mother (Imma),
O Holy Father (Abba),
Grant us your Grace.

These are two prayers that I have considered as openings to a Liturgy, vespers, or other prayer service such as in the Divine Office.

Curate Joseph.

O HEAVENLY KING

O Heavenly King,
The Comforter, the Spirit of Truth,
Who is everywhere and fills all things;
Treasury of Blessings and Giver of Life,
Come abide in us and save us for Your Name's sake. 
Amen.

O HEAVENLY QUEEN

O Heavenly Queen,
The Comforter, the Spirit of Truth,
Who is everywhere and fills things;
Treasury of Blessings and Giver of Life,
Come abide with us and guide us with Your Holy Light.
Amen.
