What does John 1:7 mean?
John the Baptist's role as a witness is central to this statement. He is sent to tell other people about the coming Messiah, which is Jesus (Malachi 3:1). "Light" was the ultimate standard for Israel's worldview. Everything good was said to be "light," evil was "darkness." This distinction not only implies good and evil, but also knowledge and darkness. Just as Moses, the Old Testament law, and the temple were small lights pointing to Jesus, John the Baptist is a tiny light leading people to the One True Light. This leading is not merely to make people see, but so that they would believe.John's ministry heavily revolved around baptism (John 1:25–28), which was already known to Jews of that time. Jews would sometimes baptize a person who wanted to convert to Judaism. But the Baptist was "converting" Jews! This is one reason he was interrogated by local religious leaders (John 1:19): why would God's chosen people need to repent and convert?