They say they put special emphasis on the Red letters because that is what Jesus was reported to have said in contrast to other scriptures that in their doubtful minds are more subjective. Yet, there is enough in Red Letters to destroy their Red Letter arguments. So they go further and selectively choose which Red Letters they will use for their heretical arguments and which they will discard because it does not fit their view.
It is not a mystery why they do this. They want a Jesus that fits the Jesus they contemplated in their own mind. A Jesus who is their buddy or spirit guide. They make the same subjective reasoning errors in their worship services and prayer. They make man the ultimate judge of truth based on their own experience and on what they wish to believe.
One major emphasis of the religious left and the red letter Christians is the idea that Jesus is a friend of sinners, that he does not come to judge anyone, and that the religious right especially is quite wrong to go on about things like abortion, pornography and homosexuality. Jesus accepted everyone with open arms, we are told, and thus we should too.But is this the case? Even if we accept their emphasis of red letter-only texts, what do we find? We find a different picture than what some of these folk are trying to portray. They often claim, for example, that Jesus said little about sin and repentance. But is that so?
A quick check of the concordance will show that even in just the red letter bits, Jesus in fact did have a fair amount to say about these subjects. Just a few passages – of many – can be referred to here.