Most people do not take their guardian angels very seriously. "I'm sure there is someone looking out for me..." and the Angel of God prayer is about as far as it goes with many people. But I think it is important to realize how much a guardian angel really does for you.
First of all, a guardian angel is a forever friend. It is someone who has been there, helping you, since birth and will always be there helping you as long as you live. It is someone you can love and rely on even when other friends won't listen or don't seem to love you. No matter where you go or what you do, you don't lose your guardian angel.
A guardian angel's principle duties are to guard you from evil, guide you to God, and teach you the ways of wisdom. They are often the messengers of God's Voice, as well. God's goodness and perfection surpass the imagination, but because an angel does not contain the greatness of God, just transports it, we can often perceive them more easily. If one has sinned and is full of shame, it is his guardian angel that he turns to before he can turn to God because his heart is not yet ready to rise its head and look God in the Face. But you ask, how do I come to know my guardian angel?
The answer is simple. If one believes his angel to be present and converses with him, or prays through him to the Father, then he will find his understanding of angels increasing. The more one prays and perceives his angel, the better able he is to hear God's answers to prayers. Also, often times by conversing with one's angel on matters that trouble him, one becomes more aware of himself and what he must do to improve. The depth and personal nature of the conversation with one's angel is precisely the thing to help clear his mind of indecision and confusion.
Just remember that there is always someone there, someone close. If you feel far away from God, you are by no means far away from your angel. Ask him for his help in your vocation... ask him to tell you what God is trying to say to you... tell him everything... put your personal petitions for your own increase in spirituality in his hands. Jesus makes you whole, He is your God and your one and all... Mary says that she is the way to Jesus... the angels and saints pray and petition for you... but your guardian angel is your own personal friend and caretaker throughout your entire life.
Angel of God, my guardian dear,
to whom God's love, commits me here.
Ever this day, be at my side,
to light, to guard, to rule, and guide. Amen.