The Christmas story is an adoption story. When Joseph discovers that his fiancee is pregnant with a child that is not his own, he is faced with a choice. In his choice to believe God's Word, marry Mary, and adopt Jesus, we see Joseph's character, his compassion, and his commitment - 3 things we will also need, by God's grace, if we are going to adopt adoption.
But Joseph, like us, was a man of imperfect character who needed a Savior. Jesus is that Savior with perfect character. Joseph, like us, was a man of imperfect compassion who needed a Shepherd. Jesus is that Shepherd with perfect compassion. Joseph, like us, was a man of imperfect commitment who needed a Substitute. Jesus is that Substitute with perfect commitment to the plan of redemption.