Who was John the Baptist, the cousin of Jesus, and what role did he play in the life and ministry of Jesus?

John the Baptist was a prophet and preacher who baptized people in the Jordan River, including Jesus. He played a significant role in preparing the way for Jesus' ministry by calling people to repentance and announcing the coming of the Messiah. John recognized Jesus as the Son of God and baptized him, marking the beginning of Jesus' public ministry.