Guardian Angels?

I've always kind of scoffed at the idea that there are guardian angels. I realize that the Bible teaches that angels do protect God's people (Ps 91:11), but I've never thought too highly of the view that God has assigned a specific angel (or angels) to guard a person. I've heard some interesting beliefs regarding this that are certainly nonbiblical. For instance, I remember hearing a sermon where the preacher went on about how our guardian angels even look like us. I had, in my mind, put guardian angels in the category of nonbiblical ideas that have crept into church theology over time and been assumed by many to be true without any Scriptural proof- along with receiving wings when we get to heaven and Satan's horns and pitchfork.

Recently, however, I read Matthew 18:10 (TNIV):

See that you do not despise one of these littles ones. For I tell you that their angels in heaven always see the face of my Father in heaven.

Now, I realize that this verse still doesn't necessarily have to mean that each child (person?) has one guardian angel assigned to them, though that is a possibility. But I admit, I was confused. Perhaps I've been wrong all this time, maybe the Bible does leave room for the possibility of guardian angels.

So I checked out D. A. Carson's excellent commentary on Matthew (page 401) to see what he had to say. I have to admit, with all due respect to a fine NT scholar, I found his explanation completely unconvincing:

The "angels" of the "little ones" are their spirits after death, and they always see the heavenly Father's face. Do not despise these little ones, Jesus says, for their destiny is the unshielded glory of the Father's presence. ...But can the word "angel" be pressed into this interpretation? Certainly Jesus teaches that God's people in the Resurrection "will be like the angels in heaven" as to marriage (22:30) and immortality (Luke 20:36). ..."their angels" simply refers to their continued existence in the heavenly Father's presence.

Really? Are Matthew's readers really supposed to pick up such a subtle nuance? Saying that believers will be "like angels" in the resurrection is quite different from saying they will be angels (and I'm sure Carson would agree, but he doesn't really deal with it here). Now, if there were some other connection between the two contexts in Matthew, he might have a point. But, one is about resurrection (Matthew 22:30), the other is dealing with a present issue ("their angels in heaven always see..."). Matthew 22 is dealing with the believer's "gender state" (for lack of a better term) at the resurrection, that idea is completely unrelated to Matthew 18. So what would ever prompt us to read that text back into Matthew 18:10? I fear that Carson has gotten too creative for his own good (and I will reiterate, Carson is a fine scholar and his Matthew commentary really is good).

In the end, I'd rather simply let the text mean what it says on the surface level- that these little children have angels in heaven. Does this mean they each have a guardian angel specifically assigned to them? Not necessarily, Jesus doesn't elaborate enough to make that a definite point. But it certainly leaves the door open for the possibility, in my opinion. And it means I can't just laugh it off anymore.