John the Baptist was a preacher sent by God to prepare the people in Isreal for the coming of Jesus Christ and to observe and confirm him as the messiah. John the Baptist was born to Zechariah and Elizabeth, even though they were by usual standards, too old to have children.
John the Baptist championed for Jesus. Once his chief duty had passed, he continued to act as a prophet, announcing God's judgment on the leadership with his brother's wife, who had him beheaded. Even before he was born, he had been set up by God to be honor worship and obey him, and he would bring many Israelites back to God.