In his book The Synoptic Problem, p. 14 (free online here), Mark Goodacre says this of reading the gospels in harmony:
“This way of reading the Gospels is not simply a recent and popular development. It is the way in which they have been read for most of their history. It proceeds in part from an embarrassment that there should be four Gospels in the Bible and not one. If we are to think of the ‘gospel truth’ and the reliability of Scripture, there might seem to be a problem in the fact that the first four books of the New Testament announce themselves as the Gospels According to [sic] Matthew, Mark, Luke, and John.”
There is something to this. Bart Ehrman has critiqued Christians who ignore the differences between the gospels saying that doing this is creating one’s own gospel, a fifth gospel. On the other hand, I know in some traditions that the canon takes precedent so that the individual gospels find greater meaning together (e.g. so that the high Christology of the Gospel of John should impact how one reads the Christology of the Synoptics).
What do you think is the benefit of reading each gospel giving attention to its separate and distinct voice and what could be the benefit of reading them together? Do we do each gospel injustice by reading them together (making a fifth gospel)? Is there a time to read the gospels together (e.g. liturgy) and a time to read them separably (e.g. historical research)?
the archives near Emmaus 
It’s bad, but not evil. There was an attempt to harmonize the gospels in the ancient Church (Google the Diatesseron). But those who accepted the canon kept the four Gospels separate. I hear sermons that move fluidly from one Gospel to another, sometimes it works, but for me it often doesn’t work. If you primary goal is an academic one, then you should never do it. But if you are engaged in the Gospels as a matter of faith, you may have some anxiety over the historical Jesus. For me, as a follower of Christ, I read the Gospels to find the Christ that the Gospel communities encountered. Therefore, I find it more rewarding viewing the Gospels in synopsis, knowing that the points that they depart from each other are the points that they emphasize. This actually gives me a deeper understanding of the Christ they encountered.
Bad. One story, different narratives and different sitz im lebens for each.
Agreed with above: Bad. I once believed that it reading them as if they were telling the same story from different perspectives was the way to do it, but this eventually led me to believe that Matthew, Mark, Luke, and John believed the same things about Jesus. Recently, however, I have gotten much more out of reading each narrative as its own separate story. Seeing where they overlap is still critical because it helps us to see exactly how they differ more clearly. To harmonize them into one is to deprive your own intellect; there is so much that is overlooked and ignored.
I think we can expect every Christian to be able to understand each Gospel on its own, but no student would try to live out a Christianity based on only one of the four books, would they?
At the other extreme from ‘harmonizing’ I have seen secular teachers of the New Testament presume to treat the principle of Markan priority as if it gives them free reign to dismiss changes or additions by Matthew or Luke or John as one and all editorial redactions (they love to do this with the Baptism story for example).
I think it is more sane to expect that a dialectic process was set in motion by the appearance of Mark’s written Gospel which acted like a lightening-rod to the memories of other eyewitnesses or ‘hearers’ of the tradition, resulting in some cases in compilations of enlarged views of a scene (not always). This serves me well anyway.
A purely academic ‘Markan’ view of the temple cleansing, for example, would have to refrain from depicting Jesus using a ‘whip of cords’ (John) and mention only his anger against the rip-off of the poor in the dove trade, leaving out the details of his disruption of the sale of oxen and sheep to the wealthier patrons as well (also John). I think the scholar has as much right to call these accents supplemental eyewitness memories as to call them ‘theologically motivated’ redactions. Certainly no preacher should be constrained to hide the harmony if he needs to get it into a sermon on Mark (with HT to John of course).
Textually, historically, or reception-ally? Textually, no, we don’t need to harmonize one blended version of four separate texts. Historically, yes, there should be aspects of the four perspectival accounts which may be combined into new re-presentations. And yet most important, for personal reception of the Gospel stories, practically speaking, tell me how in the world any christian can manage to worship four separate Jesus-es.
In a group conversation after his Waco lectures this past March, Dr Bauckham said something to the effect that some aspects of harmonization may be unavoidable. As opposed, for instance, to someone waking up this morning and saying ‘I’ll think I’ll pray to Luke’s Jesus today.’
I am *seriously* hoping he’ll have a book on these topics very soon. As you may recall, Brian, those March lectures were called, “The Gospels as History, but what sort of history”.
@Adam: I have enjoyed noticing places of difference as well. Last night I was working through the pericope of Jairus’ daugther and the woman with the twelve year hemorrhage. In Mt it appears the girl has already died, while Mk and Lk have her near death. It seems that Mt emphasizes Jesus’ ability to resurrect even more than Mk and Lk since Jairus (unnamed in Mt) comes knowing his daughter has died. This internal dynamic make studying the gospels in synopsis very interesting.
@Mark: Those are important things to recognize.
@Jeremy : I tend to agree with you. That makes sense.
@John: Very good point. When we live our Christianity we follow a harmonized Jesus to some extent. And I agree that Markan priority (chronologically) doesn’t mean Mk is superior or always right. In fact, Mk being earlier may give the authors of Mt and Lk more opportunity to “fact-check”.
@Bill: You make a good and similar point to John above. We can’t live with four Jesuses. We must harmonize to some extent.
Hmmm…This reminds me of the time when my sisters and I were talking with each other about our childhood and our parents in particular. In the midst of the visit I realized that while we had the same biological parents…we had NOT been raised by the same parents…*: )