Heb 1:7,14, Rev 8:3-4
In the Old Testament, the psalmist said that God made angels His ministers. (Psalms 104:4)
Psalms 104:4 Who maketh his angels spirits; his ministers a flaming fire:
The writer of Hebrews said that angels were sent as ministers of God to help His children. (Heb 1:7,14)
Heb 1:7 And of the angels he saith, Who maketh his angels spirits, and his ministers a flame of fire. 14 Are they not all ministering spirits, sent forth to minister for them who shall be heirs of salvation?
Also, angels go up to God with our prayers. (Rev 8:3-4)
Rev 8:3 And another angel came and stood at the altar, having a golden censer; and there was given unto him much incense, that he should offer it with the prayers of all saints upon the golden altar which was before the throne. 4 And the smoke of the incense, which came with the prayers of the saints, ascended up before God out of the angel's hand.