"His mother Mary was betrothed to Joseph; but before they came to live together she was found to be with child through the Holy Spirit. Her husband Joseph; being a man of honour and wanting to spare her publicity, decided to divorce her informally. He had made up his mind to do this."
But then "the angel of the Lord appeared to him in a dream and said, ‘Joseph son of David, do not be afraid to take Mary home as your wife, because she has conceived what is in her by the Holy Spirit. She will give birth to a son and you must name him Jesus, because he is the one who is to save his people from their sins.’"
All of this sounds quite crazy and quite impossible. For a child to exist, the intervention of a man and a woman is needed. Here the Gospel tells us about the intervention of a woman, Mary, but instead of a man it would be God himself at stake. That way, the child would be the son of a woman, and therefore a man, and the Son of God, and therefore God. Is this possible? Well the question here is if there is God or not. If there is God, being God, he can do everything because he is almighty.
In addition to this, the whole thing did not come completely out of the blue. A prophet had said centuries before, as we heard in the first reading: "The virgin will conceive and give birth to a son and they will call him Emmanuel, a name which means ‘God-is-with-us.’"
Can you set up your existence as a husband and a father upon such a story about your future wife being pregnant with God? Is this not a tale? If this really happened you would have to be very mature, be very much an adult and you would have to be in a very deep, solid and trusting relationship with that woman and with God. In fact, the biggest things in history happened only where people were so solid, so developed, so strongly based, that they dared to see beyond and above the usual business.
Only the best navigators made it possible to discover new continents. Only the best physicists could discover something radical and new like gravity or relativity. Only the most developed people could be the first to climb Everest or even to land on the moon. In the last 30 years, new technology like the internet, cloning, genoma, biotechnology etc. By the way, in the last 20 years of the 19th century the western world saw an incredible concentration of inventions like:
1876 Refrigerator, French
1876 Telephone, Scottish
1877 Phonograph to reproduce music, American
1879 Light Bulb, American
1884 TV, Russian
1886 Car, German
1890 Aeroplane, French
1895 Cinema, French
1896 Radio, Italian
If all of those things are possible for man, what is impossible for the creator of the world?
"When Joseph woke up he did what the angel of the Lord had told him to do: he took his wife to his home." I don't think he was being irrational.
We dare to ask for good surprises in our lives too. We dare to be open to whatever seems impossible, including our own happiness. We dare to be confident.