Psalm 34:7 (ESV) … “The angel of the Lord encamps around those who fear him, and delivers them.”
When David envisioned a camp of angels around him, he may have been recalling Jacob’s experience at Mahanaim (“the two camps”; Gen. 32:1–2). The angels are servants of the saints today and minister to us in ways we will never know about until we get to heaven (Heb. 1:14). 
Note other Scriptures that teach about the angels who are sent to be with the righteous:
Matthew 4:11, “Then the devil leaveth him, and, behold, angels came and ministered unto him.”
Matthew 18:10, “Take heed that ye despise not one of these little ones; for I say unto you, That in heaven their angels do always behold the face of my Father which is in heaven.”
Mark 1:13, “And he was there in the wilderness forty days, tempted of Satan; and was with the wild beasts; and the angels ministered unto him.”
John 20:12, “And seeth two angels in white sitting, the one at the head, and the other at the feet, where the body of Jesus had lain.”
1 Corinthians 4:9, “For I think that God hath set forth us the apostles last, as it were appointed to death: for we are made a spectacle unto the world, and to angels, and to men.”
1 Corinthians 11:10, “For this cause ought the woman to have power on her head because of the angels.”
Hebrews 1:14, “Are they not all ministering spirits, sent forth to minister for them who shall be heirs of salvation?”
Hebrews 13:2, “Be not forgetful to entertain strangers: for thereby some have entertained angels unawares.” 
Keep in mind that God is faithful to watch over his children. Furthermore, for every demon that fell from heaven, God has two angels to stand against them. Therefore, go out in boldness as the servant of the Lord, knowing that we have God’s strong hand and his angelic servants to protect and watch over us.
 Wiersbe, W. W. (2004).