"Perhaps no aspect of Catholic piety is as comforting to parents as the belief that an angel protects their little ones from dangers real and imagined. Yet guardian angels are not just for children. Their role is to represent individuals before God, to watch over them always, to aid their prayer and to present their souls to God at death.
The concept of an angel assigned to guide and nurture each human being is a development of Catholic doctrine and piety based on Scripture but not directly drawn from it. Jesus' words in Matthew 18:10 best support the belief: "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."
Devotion to the angels began to develop with the birth of the monastic tradition. St. Benedict gave it impetus and Bernard of Clairvaux the great 12th-century reformer, was such an eloquent spokesman for the guardian angels that angelic devotion assumed its current form in his day.
A feast in honor of the guardian angels was first observed in the 16th century. In 1615, Pope Paul V added it to the Roman calendar."
From infancy to death human life is surrounded by their (the angels) watchful care and intercession. Beside each believer stands an angel as protector and shepherd leading him to life. Already here on earth the Christian life shares by faith in the blessed company of angels and men united to God." - from the Catechism of the Catholic Church; 336.
God bless my guardian angel - he/she has been given a big job! I can recall numerous times throughout my life as I look back, where my guardian angel was working overtime! Thank you dear guardian angel. I hope I can live up to whatever reasons God has for me to still be hear, and doing well. And for my childrens' guardian angels, please protect them as well as mine has protected me.
I love this dear, little prayer. It's the first prayer my kiddos had memorized...
Guardian Angel Prayer
Angel of God, My Guardian Dear
to whom God's love entrusts me here.
Ever this day be at my side
to light, to guard, to rule, to guide.
...and this one is a beautiful one too:
Prayer to One's Guardian Angel
Dear Angel, in his goodness God gave you to me to guide, protect, and enlighten me, and to bring me back to the right way when I go astray. Encourage me when I am disheartened, and instruct me when I err in my judgment. Help me to become more Christlike, and so some day to be accepted into the company of Angels and Saints in heaven.