From the Gospel of Matthew, one learns that Joseph is a just and obedient man, the husband of Mary who has no relations with her when she conceives, the matrimonial father of Jesus, who names him and gives him a place in the line of David, who guards and defends him under God's guidance, and who raises him as a carpenter at Nazareth. He receives his vocation in dreams, and is the final link in the line of the Old Testament patriarchs who await the fulfillment of the promise.
What most stands out in Matthew's manner of presenting all of this is Joseph's tremendous faith. The commonly held suspicion interpretation of Matthew 1:18-21 is due in part perhaps to a failure to perceive the depths of the faith which Matthew attributes to Joseph. The first example of this faith is not Joseph's response to the first message of the angel in Matthew 1:24. It is presumed in Matthew 1:18, when Joseph is named as Mary's betrothed in the sentence saying that she was pregnant by the Holy Spirit. Before the angel's appearance, Joseph is the first one, together with Mary, to believe in the virginal conception of the promised Messiah. This faith is why he is called "a just man" from the start, and why he decides to separate from Mary out of reverent awe for the mystery. This faith makes him open to receive divine communications and recognize their authenticity. Joseph is a model of faith in always complying exactly and without hesitation to whatever God indicates to him. His faith is totally oriented to collaborating with the divine designs for the Savior conceived in Mary's womb and raised as their child.
In this faith Joseph is a type of first Christian, a model of faith-filled cooperation for all who follow and also call the name "Jesus," Savior. Joseph plays a most key role in the mystery of the Incarnation and is a model of righteousness for the Church.