God’s Messenger of Salvation 

At the age of 30, Jesus began his public ministry. Over the next three years, Jesus performed signs and miracles, fulfilling hundreds of prophecies that had been written about him. Jesus and his disciples preached about the coming of the Kingdom of God, encouraging people to turn from their sins and accept the salvation that God was offering them through his son, Jesus Christ.
Now Jesus did many other signs in the presence of the disciples, which are not written in this book; but these are written so that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name.
John 20:30-31