The bible pays Joseph the highest compliment: he was a “just” man. The quality meant a lot more than faithfulness in paying debts. When the bible speaks of God “justifying” a man, it means that God, the All-Holy One, so transforms a man that he shares somehow on God’s own holiness, and hence it is really “right” for God to love him.
By saying Joseph was “just” the bible means that he was one who was completely open to all that God wanted to do for him. He became joyfully, wholeheartedly obedient to God – in marrying Mary, in naming Jesus, in shepherding the precious pair to Egypt, in bringing them to Nazareth, in the undermined number of years of quiet faith and courage.