Clearly the fact that I'm an atheist and that I'm writing this means that if you happen to be a member of any Christian denomination, chances are that we have a major fundamental disagreement about the nature of Jesus Christ. I think that there is a common mistake in thinking among Christians and atheists that this disagreement has to be a defining one between us, however. I don't believe that this has to be true. In fact, I would argue that while atheists do not believe that there was anything divine about Christ, he was one of the first widely popular humanists in world history.
When analyzing antiquity, it's very hard to come up with solid facts about very many things. In those times, even though people were just as resourceful then as they are today, they didn't have the same compulsion to record things that we do today. Most people were illiterate and the people who could read and write weren't considered the intellectual elite. The literate were considered more along the lines of secretaries today, who transcribed the thoughts of the truly great thinkers. Now obviously this is a blanket statement, and there are some notable exceptions, like the Arab scholars who preserved many of the works of Greek knowledge recorded astronomical observations, but for the most part, speech was considered far more of an important medium than the written word. Now here we are, thousand of years later and we're left with a lot of incomplete and inaccurate records regarding the things that occurred in antiquity. That said, the modern day is very much derived from antiquity, so we cannot simply walk away from it and reject it as "not modern" or "not enlightened."
When we turn our attention to Jesus Christ, the first thing many of us look at is the fact that nothing was written down in a timely manner. The testaments within the bible were written decades after the death of Jesus. There are Roman documents from the time that discuss Jesus, so we can safely assume that Jesus actually did exist. Christians believe that the holy spirit worked through the various writers to convey to people the exact words of Jesus, thereby sidestepping the question of the accuracy of teachings that were decades old by the time they even started being recorded.
What we know is that the New Testament was compiled based on interviews with eye witnesses, and therein lies a problem. As has been scientifically concluded in recent years, memory is a fragile thing. Memories are easily altered and distorted based on perceptions, suggestions, and beliefs. That's why there have been numerous documented cases of crime victims identifying the wrong suspect after a crime. So, thirty years after the death of Christ, we can only believe that the words and deeds of Jesus were distorted a great deal, particularly by the people who followed him and believed in his message. For example, how would we know Martin Luther King Jr. in the modern day if there were no written or video accounts of the speeches he gave? I would argue that very few of his exact words would be preserved, although the essence of his message would be very much preserved.
I would also argue that in antiquity, people had a very real tendency of mixing the mundane with the supernatural. For example, in ancient Greece, people believed that the sun moved across the sky because it was pulled by the chariot of the god Helios. A prominent sect of Buddhists decided that Buddha was a god rather than a man despite the fact that this is a contradiction of one of the main tenets of the religion. Greek and Roman mythologies were full of stories of various figures being gods or the sons of gods and performing great deeds that would be outside of the realm of normal human beings. In fact, a religion without these elements would have a difficult time finding traction among ancient people. The fact is that there is really nothing new or exceptional about the Jesus story within the context of the ancient world.
So that's a summary of why it is both reasonable and logical to doubt the validity of the full mythology of Jesus that is embraced by the Christian religion. That said, even a non-believer like myself should objectively look at the message of Jesus and evaluate it on its own merits rather than simply discarding it. As I said earlier, even if the exact words of Martin Luther King Jr. were not recorded, the fundamental message would have been remembered and his teachings would probably still have a transformative effect upon society, even if it would take longer for it to spread by word of mouth. So who was Jesus?
Jesus was a religious reformer! His message was that the God of the Old Testament was too harsh to be accurate and that if there was a benign creator, what he really wanted was for people to live peacefully together and be faithful to God. The first part of his message is one of the core underpinnings of Western society while the second part is hardly unexpected given the fact that he was a religious figure. Again, comparing his to Martin Luther King Jr., we would not expect him to preach a message of racial equality and reform and not ground it in his Christian background. Jesus was the same. Once you discard the religious elements of Jesus' teachings, his core tenets were: the golden rule, loving your enemies, repentance and forgiveness, not judging others. In other words, Jesus wanted peace and coexistence. While I think that much of Jesus' actual words were lost, the core tenants were recorded intact, and that they were consistent with enlightened thought.
While atheism is the rejection of supernatural forces upon our lives, one of the things we need to do is come to some sort of realization of the synergies between our lack of belief and the belief systems of those who do believe. It would be wonderful if we could all just be human beings dealing with each other, and most of us believe that the ideal way of achieving this would be through the rejection of ancient outdated dogma upon modern society. Sine that isn't going to happen, we need to figure out a way of dealing with everyone else that doesn't necessarily categorize them as "the enemy" or "the other." It is true that Western civilization is largely based on the Renaissance, which was when people rejected the church's control over every facet of society while embracing the emphasis of reason of the Greeks, but there is a very humanistic moral underpinning that also exists within our civilization. We can come up with non-religious reasons for morality and there are certainly disagreements among many of us regarding what is and is not moral, but the bottom line is that as a culture, we tend to try to do what we consider good.
In my opinion, it would therefore be more productive for Atheists and Christians to work towards understanding and common goals based upon similarities in our ideologies rather than working towards hostility based on our differences. If what we want is consistent with the teachings of Jesus regarding human behavior towards one another then it would not be inappropriate to adopt Jesus Christ within our own context, which is that of an early humanist philosopher. It could even be appropriate for an atheist who identifies with the teachings of Jesus to consider himself a Christian atheist. It should likewise be possible and even useful to take the humanist, rational elements of other religions. Just as science places an emphasis on ancient scientists, many of whom were wrong but "onto something", one does not need to accept superstitious dogmatic beliefs in order to find the value of certain beliefs that emerged from antiquity.