Joseph knew His wife was pregnant by someone other than him. The only possibility seemed to be that Mary was an adulteress. But in a dream, an angel told Joseph that Mary had conceived by the Holy Spirit (Mt 1:20).
Would you believe this miracle? Would you believe something that had never happened before? Would you believe something that you didn't and couldn't understand? Would you believe something from a dream? When Joseph believed in the virgin conception, he made one of the greatest acts of faith ever. If he had not made this great act of faith, he would not have been at the first Christmas.
If we are to meet Christ this Christmas, we must have faith, as Joseph had faith. A true Christmas is a matter of faith. We walk and live by faith (see 2 Cor 5:7), and we have Christmas by faith. Without faith, it is impossible to please God this Christmas or any time (Heb 11:6), and the purpose of Christmas is to please Christ. After all, it is His birthday celebration.
Very few people were aware of the first Christmas, even though a star announcing Jesus' birth blazed across the sky (Mt 2:2). At this Christmas, the few or many who will meet Christ will be men and women of faith, people like St. Joseph. Have faith in the Christ of Christmas.