Luke 1:15 NIV
For he will be great in the sight of the Lord… and he will be filled with the Holy Spirit even before he is born
Doctor Luke must have been fascinated with the concept of being filled with the Holy Spirit. According to tradition, Luke was a Greek doctor, so his medical education would no doubt be dominated by the great physicians of Greek antiquity, the most famous of which was surely Hippocrates, who had lived some 500 years before either Luke or Jesus. Hippocrates wrote far more than just the oath for which he is famous, and one of the things that he particularly emphasised was the importance of observation. Indeed, observation is a key skill for physicians today, as much as it was then.
Luke, trained in observation, became one of Paul’s greatest friends and companions, accompanying him on his journeys, taking care of him and his missionary band when they were unwell. He saw many amazing things during those years. One of the things would have made a deep impression was the phenomenon which Paul identified as the Holy Spirit. Luke wrote about the Holy Spirit repeatedly, in both of his books. He saw first hand the effect that the Holy Spirit had on people, extraordinary things like supernatural knowledge, an ability to prophecy, speaking in strange tongues, healing. He became convinced that these things he had witnessed were a demonstration of the supernatural power of God at work in people. What is more, it is likely that he not only observed the Holy Spirit at work in people but experienced the same Spirit at work in himself. He knew what the power of God was capable of when it took hold of people.
So though Luke never met either John the Baptist or Jesus, he did meet God in the form of the Holy Spirit, which he came to understand not as an impersonal force but as a spiritual expression of the person of God, in the same way that Jesus was a physical expression of the Father. So Luke was like us modern Christians. His experience of God was not physical, in the sense that he had taken hold of Jesus’s hand or sat and listened to him speak, but spiritual. He had seen and experienced God at work in ordinary people and himself, but he had not seen and experienced God in a physical form as the disciples did.
Luke was no doubt an enquiring person. He knew that the Holy Spirit had been a feature of the Jewish worldview since time immemorial. But he also knew that until the time of Jesus most people understood the Spirit of God as something that came on people from time to time when those people were called by God to perform extraordinary deeds. He knew that the concept of being filled with the Spirit from before birth would have been an unusual idea for Zechariah to grasp, and that is why he recorded it. Zechariah would have been stunned by the idea that his son would be filled with the Holy Spirit from before his birth. He would not just be a Nazirite, devoted to God, but a man empowered by God himself. And not just for a season of his life, but for all his days. He would be a great man.
Modern doctors seem to have a lot more trouble comprehending the spiritual than Luke did or any of his first century readers. We learn clinical skills which consist of listening and examination, which is what Hippocrates would have called observation, and which is the cornerstone of making a diagnosis. Yet though the effects of the Holy Spirit in the lives of Christians are often clearly visible, our scientific rationalistic worldview often prevents us from attributing these things to the Holy Spirit, because we associate such ideas with archaic ignorance. We look for other causes in a person’s life, reluctant to attribute change to a supernatural spiritual power, “hocus pocus.” It is our atheistic world view that prevents us from seeing the Holy Spirit, not the absence of the Spirit.
Why did early Christians believe in the existence of a Holy Spirit? First, they did not start with the belief that God did not exist. The idea of God, indeed of many gods, was normal at that time. Second, the Holy Spirit had been promised by Jesus, so they were expecting it. Third, they had the testimony of people like John to show them that a person could indeed be empowered by God’s spirit. But when they saw the effects of the Holy Spirit coming on people they were stunned, for it gave them the ability to act and behave in ways that were not normal for them. The same was true of John the Baptist. He said and did things that indicated a greater power at work within him than that which would be expected of a mere mortal. This was what the angel had promised, and what marked him out as a being filled with the Holy Spirit. These things are the stuff of greatness. Perhaps not greatness in the world’s eyes, but certainly greatness in the eyes of the Lord.