Matthew, Chapter 1, verse 19-20:
19 Joseph her husband, since he was a righteous man, yet unwilling to expose her to shame, decided to divorce her quietly. 20 Such was his intention when, behold, the angel of the Lord appeared to him in a dream and said, “Joseph, son of David, do not be afraid to take Mary your wife into your home. For it is through the Holy Spirit that this child has been conceived in her.
Even righteous people become afraid at times but Mark Shea a catholic writer points out that Joseph being a devote Jew may have had Holy fear as the basis of his being afraid.
”Modernity assumes it was because he thought her guilty of adultery, but the typical view in antiquity understood the text to mean he was afraid of her sanctity — as a pious Jew would be afraid to touch the Ark of the Covenant. After all, think of what Mary told him about the angel's words: "The Holy Spirit will come upon you, and the power of the Most High will overshadow you; therefore the Child to be born will be called holy, the Son of God."
We should follow the example of Joseph and be not afraid to take Mary into our home!