Joseph of Nazareth was a fairly ordinary man up until the moment he found out that he fiancé Mary was pregnant. Instead of letting pride or anger rule him, Joseph chose to embrace mercy, he was willing to divorce her quietly.
Having demonstrated this strength of character, an angel of the Lord came to Joseph in a dream to tell him that God had chosen him for a monumental task: Adopt the Messiah.
Joseph may have been an ordinary carpenter, living in the unimportant village of Nazareth, but when he obeyed God's command by marrying Mary, Joseph became an example of faith and obedience that we would all do well to imitate.