Adherents of certain Christian traditions believe that God assigns guardian angels to watch over individual human beings. Catholics have the most elaborate system of doctrine and devotion to guardian angels, including a special feast day dedicated to them, the Feast of the Guardian Angels on October 2.
Unlike most Protestant traditions, the Catholic tradition includes the practice of praying to saints and angels. Catholics are encouraged to pray to their guardian angels for strength, wisdom, and protection. The Angele Dei is an example of a common prayer to a personal guardian angel.
Many see references to guardian angels in Genesis 28-29, Exodus 12-13, Psalm 90:11, and Matthew 18:10 of the Bible.