A Light in the Darkness
John the Baptist's mission was to prepare the people of the coming of Jesus, the light. We don't read of John being around the temple and following in the footsteps of his father. Instead he was a prophet who preached an unfiltered message; the message he received it from God.
Apparently John did not want to be a priest. Even though this was so and may have seemed disappointing to his parents, you remember that the angel told Zacharias that the child would be a joy and delight. John message was to improve the passages for the coming of the king. You might say he had a one note song, repent and be baptized.
Repentance is a continual need. Baptism represents cleansing. The repentance of each is different because the sins of each are different.
The analogy of Jesus to light is amazing. In the physical world of light no amount of darkness can extinguish even a small light. Light can be absorbed or reflected. Spiritually the same is true. No amount of darkness can extinguish it. The light is either absorbed or reflected. For some it is a deflection. Nevertheless the light is and always will be. Praise the Lord.