The most common explanation for the angels of the churches is that they are the pastors of those churches. Of course, pastors is not proper terminology for the late 1st century. "Bishops" would be the appropriate term.
There's a pretty severe problem with this interpretation, however. The angels of the churches are already symbolically represented by the seven stars in Jesus' hand. If the angels symbolically represent the bishops, then you've got stars representing angels that in turn represent the bishops.
That is not typical for the Bible. One symbol does not typically represent another symbol.
Most people don't realize that our English word angels come from the Greek word angelos in the Bible. "Angel" is what is known as a "transliteration" of the Greek word, rather than a translation.
What that means is that rather than actually translate the word into English, the Greek word has begun to be used in English just the way it is.
Often this is not a problem. In the Bible, however, failing to translate a word can lead to misunderstandings, whether minor or major. The word seraph is a good example. It is left untranslated in Isaiah 6, but seraph actually means something.
It is the same way with angelos.
Angelos is used in the New Testament 186 times. In the King James Version, it is left untranslated 179 of those times. The other 7 times, however, it is translated "messenger," which is what it means.
For example, in Matthew 11:10, there is a prophecy about a "messenger" who would be sent before Jesus to prepare his way. That messenger is John the Baptist, and the Greek word used there is angelos.
The same is true in the parallel passage in Mark 1:2 and Luke 7:27. In Luke 7:24, men sent from John to Jesus are referred to as "messengers." Again, the Greek word is angelos [Actually, it's angelloi because it's plural].
So if the angels of the churches are not symbolic of bishops, but are literally the messengers of the churches … who are these messengers?
This is where things get fascinating.
There is a famous early Christian letter called First Clement. It is very likely the earliest Christian writing outside of the New Testament.
Interestingly enough, though it's been called First Clement for 19 centuries, there is nothing in the letter saying that Clement wrote it. The letter says it is from the church in Rome to the church in Corinth.
Of course, the church in Rome doesn't write letters any more than Wal-Mart or Google could write a letter. Someone with authority writes a letter on their behalf.
There is one ancient piece of evidence that Clement had such authority.
That quote is from The Shepherd of Hermas, a book written in Rome in the 2nd century (2nd book, 2nd vision, 4th chapter). The old woman represents the church in his vision, but the point we want to get from this reference is that Clement is the one with permission to send books to foreign countries.
I would like to suggest this is because Clement's position was that of messenger of the church in Rome.
I've already addressed elsewhere on this site that Clement could not have been the lone bishop of Rome in A.D. 96, when First Clement was written (see sidebar for brief review).
However, Irenaeus, writing in A.D. 185 (or so) gives a list of the bishops of Rome going all the way back to Peter, and Clement is third after Peter (Against Heresies III:3:3). In Irenaeus' day, Rome, as well as all other churches, would have had one lone bishop.
But why would Irenaeus single out Clement as that one if there were several bishops in Clement's day?
The most likely reason, in my opinion, is that Clement was the messenger of the church in Rome. His name stood out and was remembered.
He was the one who sent letters, as The Shepherd of Hermas suggests, and he was the one who received them, as the book of Revelation suggests. (Jesus' letters in Revelation 2 and 3 were sent to the angels of the churches.)
This can be nothing more than a theory because I can't cite any historians who have said the same thing; however, the arguments for this position are a lot more compelling than simply guessing that maybe the angels of the churches are the bishops of those churches.