Red-letter Christian is a name a group of politically activist evangelicals have used to describe themselves. They privilege the words of Jesus, which are printed in red in some Bibles, over other parts of the Bible.
I have a few further observations about this.
If you have a red-letter Bible, flip over to Revelation. You will see that the seven letters to the seven churches are in red print. Now these obviously are not sayings of the historical Jesus. These are a part of New Testament prophecy. Just as the Hebrew prophets often spoke in the name of God–“Thus sayeth the LORD”–so New Testament prophets sometimes spoke in the name of Jesus.
As the seven letters show, the words New Testament prophets spoke in the name of Jesus sometimes show up as quotations. This probably accounts for at least some of the community theology (Gemeindetheologie in German) in the words of Jesus. Scholars claim, with good reason, that many sayings of Jesus got adapted by Matthew’s community, for example, to fit its situation sometime after 70 CE. More than that, it is certainly possible that first century prophets actually created some of the sayings of Jesus in the gospels.
This is a problem for some of us, but the New Testament church probably wouldn’t understand our problem. Jesus said it. What difference does it make whether he said it during his earthly life or through the mouth of a prophet later? The historical Jesus is a modern idea. It is our reductionism that denies the possibility that the institution of prophecy truly reflected Jesus.
But if the prophets spoke with authority, so did apostles, apostolic transition figures, and others who produced the New Testament. Notice how when Matthew finds it necessary to modify Jesus’ absolute prohibition of divorce, he just inserts new words: “except for adultery”(Matthew 5:32). Paul, on the other hand, boldly deals with a new problem by giving his opinion over against Jesus (1 Corinthians 7:12). Giving extraordinary authority only to the words of Jesus seems questionable.
Another observation is that the Red-letter Christians seem to assume that Jesus’ role is primarily that of an ethical teacher. I doubt that the earliest Christians saw it that way. Even the majority of rank-and-file Christians today probably see Jesus more as healer/redeemer than as ethical teacher. My sense of my fellow clergy (Protestant Mainline) is that they often think this is a defect in the laity.
I am sure I remember from back in the days when I devoured the writings of C. S. Lewis that he somewhere said that we have no shortage of great ethical teachers. He may have referred to Confucius and the Stoics. We have not followed their teaching. What makes us think people will likely follow the more stringent teachings of Jesus? What we really need is someone to give us something to do about the reality that we are not very ethical.
Why isn’t the Passion Story printed in red instead of the sayings? Why aren’t the miracles printed in red instead of the sayings? It says something about our assumptions.
My final observation is that I don’t see the Red-letter Christians dealing with the full content of the sayings of Jesus. Many of his sayings were not ethical, but prophetic and eschatological. What would you call the parables? What they seem to be looking for are sayings that would align Jesus with Gandhi and pacifist or pro-Welfare State policies. I read the same Bible they do, but I really don’t see that.