Attention. Joseph was paying attention. The message from God was unusual. That is why an angel brought the message. The medium of the message and message were perfectly coordinated. After the angel said, "don't be afraid," the angel then said, "Mary is pregnant because God has chosen her to be the mother of Jesus. She is pregnant by the Holy Spirit." Then the angel quoted Isaiah to support this statement with Scripture. All of us can see that Joseph's is not a normal experience.
Joseph had the courage and faith to go with the story, marry Mary, and rear Jesus as his son.
When any of us is asked to be in relation with Jesus, the process of entering into and growing in that relation is the same for us as it was for Joseph.
First, there is a messenger. The messenger's first words must be, "don't be afraid." We are not afraid of people when we know that they love us without question or condition. Another way to say it is that nothing in this world will separate us from the love of God--not in life, not in death. This is a paraphrase from St. Paul. The safety of the messenger determines whether or not we receive the message as Good News. When people come to a saving knowledge of Jesus' love, normally someone in a safe relation with the person carries that message. The witness of an abusive parent is never trusted, no matter how theologically accurate the statement. The preaching of a tyrant who seeks to control and manipulate never communicates the love of Jesus no matter how eloquent. If you are blessed with a saving knowledge of Jesus, it is likely that you heard it from someone who loved you without condition. You heard it from someone who does not make you afraid.
Holy Scripture has a critical role in coming to know Jesus. The teaching from the prophet Isaiah must have been known to Joseph. The Scriptures give us images and metaphors that help us to see God at work when we encounter God. Scripture is the long history of salvation. When we are familiar with it we can recognize the patterns of God revealing complete love. If you love someone, say a child, enough to want them to know Jesus in a saving and healing way, teach and share Scripture with them. Then they will recognize the love of God when it comes to them.
So Joseph, based on the "no fear" message from the angel, the direction of the message, and the content of the Scriptures, did as he was bid. When the baby came, Joseph took him to his heart. Before birth, babies lie under their mother's heart. After birth, a baby must grow in the hearts of the parents. Jesus grew in Joseph's heart.
Each of us is like Joseph. Jesus must grow in our hearts in the way that a child can grow in the heart of a parent. It may be that the reason God gives us humans beings in the shape of babies is so we will have a chance to learn to love without condition. One mother observed, "I really didn't know what sacrificial love meant until we had a baby. The wants, needs, and best interests of that child become more important to us than our own needs. That baby cried and we responded, even if we were tired, or sleepy, or cranky. The baby had first call on our life, and we loved it."
It is likely that Joseph and Mary had the same feelings about Jesus that most parents have when they have a baby. There is a lot of hope. There is hope that somehow, the child's life will be better than our own lives. There is the hope that the grimness and danger of life will not touch the child. It may be that one way hope comes into life is in the shape of a baby.
Joseph heard an extraordinary message. The angel said, "this child is 'God with us'"; (God with us is what Emmanuel means.) So the baby Jesus is a source of hope, not just for Mary and Joseph, but for all of humankind for all of history and for all eternity.
This is a big assignment for a baby. This is a big assignment for the daddy of this baby. If Mary and Joseph had failed in their mission, we would all be in terrible trouble. But they didn't. Jesus grew up to be the absolute fulfillment of "God with us." His life, his sacrificial love seen in his death on the cross, and his triumph in resurrection, change everything. He gives us hope. We can hope with joy for the restoration of all relationships that are part of his life, death, and resurrection through our Baptisms and confessions of faith. The angels are saying to us, "Don't be afraid. God is with us. You are loved by God without condition and without exception."