Why is the birth of this man having this kind of effect on the world?

"Sometimes the most important things in the world pass before our eyes, and we don't see them. And so they don't have the impact on our thought and our emotions the way they could if we just stopped and pondered for a moment. This is especially true of the significance of the birth of Jesus Christ. There are undisputed historical effects of the birth of Jesus Christ that are so huge and so important that we miss them—like we miss the sky or the air or the ground under our feet. We never give them a thought. But when you think about them, they're staggering….the impact of Jesus Christ on this world has been so immense that even before we turn to the Bible, we are confronted with a staggering choice this morning in relation to the man Jesus Christ….First, because Jesus Christ was born, one third of the world's population today calls itself Christian….Not only that, Christianity is the most extensive and universal religion in history. There are Christians and Christian churches in every inhabited country in the world. And in two-thirds of the world's 223 countries the population is over 50% Christian. So the first indisputable significance of the birth of Jesus Christ is that the life of this man has influenced more people over the course of human history than any other single man. Buddha, Confucius, Mohammed, or even Moses do not compare in the extent of their influence on history and the world….Second, virtually every person in the modern western, and most of the non-western, world calls this year 1987. But the reason bankers and butchers, and car dealers and doctors, and teachers and attorneys, and computer programmers and presidents date their checks '1987' is because Jesus Christ was born 1,987 years ago. No other man in history has been accorded the almost universal honor of dividing history in half—and with such definitive influence that millions who do not call him Lord are forced to bear witness daily to his tremendous, on-going importance in the world by using the date 1987….In other words the religious, historical, and cultural significance of Christmas—the birth of Jesus Christ—is so huge that no one can begin to give it an adequate description. Now that fact, in and of itself, before we even turn to the Bible, confronts you and me with a profound choice: will we ignore this man and take him lightly in spite of his being the most influential man who ever lived, or will we inquire earnestly into who this man was and why he has changed the world so deeply? Why is the birth of this man having this kind of effect on the world?" (John Piper)