When thinking of Guardian Angels, people have all sorts of notions as to what they are, most of which involve either a small man dressed in white with wings and harp standing on the right shoulder and arguing with a devil (often weakly), such as this:
Or perhaps some schmaltzy and sentimental image, such as this:
Rarely does anyone envision a Guardian Angel as who, you know, can actually be a guard, such as this:
While we are on the topic of the depictions of angels, we should note that angels, in fact, have no bodies; they are pure intellect. We show them in the form of human beings to indicate their intelligence and free will and with wings to symbolize their swiftness in carrying out God's commands.
It is, I suspect, the above conceptions of angels that led J.R.R. Tolkien to write to his son, Christopher, on the 8th of January in 1944, J.R.R. Tolkien urging him to "remember your guardian angel. Not a plump lady with swan-wings!"
In another letter, written between the 7th and the 8th of November of the same year, the elder Tolkien relates to the same son an experience he while participating in the Forty Hours Devotion in the church of St. Gregory:
Despite his fumbling language to describe this experience (such moments of grace are always difficult to relate), Tolkien describes the Guardian Angels as "God's very attention, personalized," though he was not sure if he was correct in this description.
Sixty-seven years late, Pope Benedict XVI would describe the Guardian Angels as "ministers of the divine care for every human being" (Angelus Address, 2 October 2011). Tolkien's description of the Guardian Angels was both profound and correct.