"See, I am sending an angel before you, to guard you on the way and bring you to the place I have prepared.  Be attentive to him and heed his voice. Do not rebel against him, for he will not forgive your sin. My authority resides in him.  If you heed his voice and carry out all I tell you, I will be an enemy to your enemies and a foe to your foes.
 "My angel will go before you and bring you to the Amorites, Hittites,
Perizzites, Canaanites, Hivites and Jebusites; and I will wipe them out.
Judith 13:20 (Vulgate/Douai)
As the same Lord lives, his angel has been my keeper both going hence and abiding there, and returning from there here; and the Lord has not suffered me his handmaid to be defiled, but has brought me back to you without pollution of sin, rejoicing for his victory, for my escape, and for your deliverance.
 The angel of the LORD, who encamps with them,
delivers all who fear God.
For God commands the angels
to guard you in all your ways.
 With their hands they shall support you,
lest you strike your foot against a stone.
 You shall tread upon the asp and the viper,
trample the lion and the dragon.
but the prince of the kingdom of Persia stood in my way for twenty-one days, until finally Michael, one of the chief princes, came to help me. I left him there with the prince of the kings of Persia,
"See that you do not despise one of these little ones, for I say to you that their angels in heaven always look upon the face of my heavenly Father.
She was so overjoyed when she recognized Peter's voice that, instead of opening the gate, she ran in and announced that Peter was standing at the gate.  They told her, "You are out of your mind," but she insisted that it was so. But they kept saying, "It is his angel."
During (the) night Paul had a vision. A Macedonian stood before him and implored him with these words, "Come over to Macedonia and help us."
Are they not all ministering spirits sent to serve, for the sake of those who are to inherit salvation?
This is the secret meaning of the seven stars you saw in my right hand, and of the seven gold
lampstands: the seven stars are the angels of the seven churches, and the seven lampstands are the seven churches.
"To the angel of the church in Sardis, write this:
" 'The one who has the seven spirits of God and the seven stars says this: "I know your works, that you have the reputation of being alive, but you are dead.
Why we need the Guardian Angel:
1 Peter 5:8
Be sober and vigilant. Your opponent the devil is prowling around like a roaring lion looking for (someone) to devour.
The huge dragon, the ancient serpent, who is called the Devil and Satan, who deceived the whole world, was thrown down to earth, and its angels were thrown down with it.