An innumerable company of angels are at the service of the Church.

Hebrews 12:22-24

22 But ye are come unto mount Sion, and unto the city of the living God, the heavenly Jerusalem, and to an innumerable company of angels, 23 To the general assembly and church of the firstborn, which are written in heaven, and to God the Judge of all, and to the spirits of just men made perfect,  24 And to Jesus the mediator of the new covenant, and to the blood of sprinkling, that speaketh better things than that of Abel. 

Hebrews 1:14

14 Are they not all ministering spirits, sent forth to minister for them who shall be heirs of salvation?

Angels are our servants

The appearances of angels

Hebrews 13:2

2 Be not forgetful to entertain strangers: for thereby some have entertained angels unawares.

Angels are listening

Psalm 103:20

20 Bless the LORD, ye his angels, that excel in strength, that do his commandments, hearkening unto the voice of his word. 

Bringing gifts from heaven

The open heaven