The Catholic Church teaches that we have guardian angels, even setting aside a day to honor them (October 2).
My personal favorite depiction is the one Pat Brady (and carried on by Don Wimmer) gave to Pasquale's guardian angel in the comic strip, Rose is Rose.
Above you see that Pasquale's guardian angel normally presents a facade similar to the appearance of Pasquale himself; until trouble presents itself. Then, the guardian angel assumes a masterful, powerful, awe-full persona.
Somehow I have come to picture the angels who announced good tidings of great joy to the shepherds, who surrounded the cave-stable that night in Bethlehem, to be the latter: the kind who would bring us mortals to our knees with their numinosity and glory.
Oh, and by the way: the strip above appeared on December 14, 2008: the feast day of St John of the Cross. And my birthday ... for future reference.