The most likely author of Zechariah 14:9 is the prophet Zechariah himself. Zechariah was a prophet who lived in the 6th century BC and was one of the post-exilic prophets who prophesied to the people of Judah who had returned from exile in Babylon. He was a contemporary of Haggai, and together they encouraged the people to rebuild the temple in Jerusalem.

From an evangelical Christian perspective, Zechariah is considered to be a true prophet of God who spoke the words given to him by the Holy Spirit. His prophecies were fulfilled in the life and ministry of Jesus Christ, particularly in the events surrounding his death and resurrection. In Zechariah 14:9, Zechariah speaks of a future time when the Lord will be king over all the earth, and his name will be the only one that is worshipped.

Evangelical Christians believe that the Bible, including the book of Zechariah, is the inspired and inerrant word of God, and that its prophecies will be fulfilled in the future. They view the book of Zechariah as a source of hope and encouragement, pointing to the ultimate victory of God over evil and the establishment of his kingdom on earth.