Today is the feast of the Holy Guardian Angels. The prayer to the guardian angels has been present in the Church since at least the beginning of the 12th century.
Guardian Angel Prayer:
Angel of God, my Guardian dear, to whom God's love commits me here, ever this day be at my side, to light and guard, to rule and guide. Amen.
Guardian Angel Quotes:
"The servants of Christ are protected by invisible, rather than visible, beings. But if these guard you, they do so because they have been summoned by your prayer. "
~ St Ambrose
“Let us affectionately love His angels as counselors and defenders appointed by the Father and placed over us. They are faithful; they are prudent; they are powerful; Let us only follow them, let us remain close to them, and in the protection of the God of heaven let us abide.”
~ St Bernard of Clairvaux
"God's universal providence works through secondary causes . . . The world of pure spirits stretches between the Divine Nature and the world of human beings; because Divine Wisdom has ordained that the higher should look after the lower, Angels execute the Divine plan for human salvation: they are our Guardians, who free us when hindered and help to bring us home."
~ St Thomas Aquinas