On Liturgical Spirits

Tob 12:12, 15 When thou didst pray with tears, and didst bury the dead, and didst leave thy dinner, and hide the dead by day in thy house, and bury them by night, I offered thy prayer to the Lord…For I am the angel Raphael, one of the seven, who stand before the Lord.  
Psa 141:2 Let my prayer be set forth before You as incense; the lifting up of my hands as an evening sacrifice.

Heb. 1:14 Are they not all ministering (Grk. λειτουργικὰ: liturgical) spirits sent out to serve for the sake of those who are to inherit salvation?

Rev 8:3-4 And another angel came and stood at the altar with a golden censer, and he was given much incense to offer with the prayers of all the saints on the golden altar before the throne, and the smoke of the incense, with the prayers of the saints, rose before God from the hand of the angel.

St. Hilary of Poitiers ca. 300-368

There is positive grounds to the teaching that the angels preside over the prayers of the faithful. They offer to God every day the prayers of those who have been saved. (Comm. in Matt. 18,5)