October 2 is the feast day of Guardian Angels.
The concept of guardian angels is expressed in the Old and New Testaments, and Jesus makes their existence explicitly clear in the Gospel of Matthew, when he says, “See that you despise not one of these little ones: for I say to you, that their angels in heaven always see the face of my Father who is in heaven” (18-10).
Jesus tells us that everyone, even small children, has a guardian angel, and the mission of these angels is to protect us throughout our lives and guide us to heaven. But as St. Thomas Aquinas wrote, angels cannot act directly upon our will or intellect, so they can only guide us to heaven if we want to go there. They can act on our senses and imaginations, encouraging us to make the right choices and live as Jesus wants us to.
The prayer to the guardian angels has been recited since at least the early 12th century: “Angel of God, my Guardian dear, to whom his love commits me here, ever this day be at my side, to light and guard, to rule and guide. Amen.”