In 1768 the French skeptic Voltaire wrote a poem in which appeared his famous line; "If God does not exist, it would be necessary to invent Him". Since then, other skeptics have taken their turns at interpreting this statement, but it seems clear from the whole poem that Voltaire, a deist who distrusted all organized religion, was arguing for religious tolerance. He did so on the basis of what can be known for sure about God from what is evident in nature—as well as for the need for an anchor for the moral universe.
It seems to me, however, that one might take Voltaire's argument one step further. We might claim that unless Christ exists, we would be forced to invent him as well.
My argument? Well, it has become more and more evident, especially since Voltaire's time, that the past existence or beginnings of the universe depends on the existence of some First Cause or God—otherwise, what was it that "banged" or caused the Big Bang? But it is also becoming more evident, as science progresses, that the universe has only a limited and ultimately doomed existence. Eventually the universe, and everything in it, including humanity—if we can manage to keep from blowing up out home planet in the meantime—are going to snuffed out in what scientists call a "heat death", meaning the exhaustion of all energy, and with that, the cessation of all life.
Of course, back when people used to really believe we really have immortal "souls" or are that we are heavenly spirits just spending a few years trapped in material bodies, even this problem wouldn't be of any major significance. But science has pretty much dispelled those quaint notions as well. So what is left for us? Not much, unless we are satisfied with the image of a God who put the whole process of evolution into motion just to keep himself amused until he gets bored with this show and turns to something else.
Instead, this is where Christ—or at least someone like him—comes into the picture. We need someone who can demonstrate, by achieving it himself, that death, whether it be of the universe or simply of ourselves, can be truly overcome. Otherwise, for us humans at least, everything is lost.
Of course, the job description is exacting. It takes a very special person. A mere wise man or prophet, be he Socrates, or the Buddha, Moses, or Mohammed is not enough. They can only point to the truth as they see it or as it might be revealed to them. For that matter, not even Jesus of Nazareth—that is, Jesus as seen by the historians—can make the grade. It is only when Jesus is seen as the Christ of faith, the Son of God, who "dying destroyed our death, and rising restored our life", that he can truly accomplish the job.