In Luke 1 we read about Mary's interaction with the angel Gabriel who tells Mary she is favored by the Lord and will give birth to Jesus who will "be called the Son of the most High." Mary's reaction goes something like this...
1st shock - v.29 "Mary was greatly troubled and wondered what kind of greeting this might be" ... v.2 tells us that the angel says to Mary "Do not be afraid"... I don't know about you, but seeing an angel would be pretty out of the ordinary, I think I would be pretty afraid at first too. Please don't miss how amazing this initial interaction is... Mary is being spoken to by an angel!!!
2nd- Confusion/denial v.34 "How will this be...since I am a virgin?" The angel goes on to tell Mary of the miracle that will occur in her through the Holy Spirit. The Holy Spirit is part of the trinity, 3 in 1, the Holy Spirit is used in scripture interchangeable to refer to God himself and indeed is God himself. This is complex for us to wrap our minds around but instead of giving into thoughts of unbelief let's praise God for how magnificent he is! He is immeasurable and complex and worthy of our worship not our criticism or critique.
3rd- Acceptance- Mary says, "May it be to me as you have said."
Now for Matthew's account from Joseph's perspective.
1st- shock/hurt- Joseph was betrothed to Mary. The ESV study bible explains what betrothed means. There were 2 stages to betrothal. The 1st stage was different from engagement, the parents chose who their son would marry. The 2nd stage involved official arrangements and prenuptial agreement, "a legally binding contract that could only be broken by a formal process of divorce." Now that we have a better understanding we can imagine the shock Joseph feels!At this stage is their betrothal Mary is referred to as his wife and now he finds out he is pregnant! Devastating! At this point he doesn't know that the child conceived in Mary is from the Holy Spirit, we see this in v.19"And her husband Joseph, being a just man and unwilling to put her to shame, resolved to divorce her quietly."
2nd- fear - An angel appears to Joseph in a dream and his first words are, "Joseph, son of David, do not fear to take Mary as your wife..."
3rd- obedience/acceptance v. 24&25 "When Joseph woke up from his sleep he did as they Lord as the Lord has commanded him and took Mary home as his wife. But he had no union with her until she gave birth to a son."
Upon hearing from the angels the news of Jesus' miraculous birth Mary & Joseph could have been disobedient in unbelief. Rather, Mary said, "The Lord called has called me blessed" and Joseph, "did what the Lord had commanded." Both accepted the hardship and suffering ahead as they prepared to have the Son of God in their family who many would reject (eventually crucify) and some would embrace as their Savior. God picked Mary & Joseph to be Jesus' earthly parents and by their responses to His call He knew who He was choosing (of course, since He is all knowing :) ). He was choosing who He knew would be obedient and endure hardship because of their fear of the Lord (fear of dishonoring the Lord).
The Lord calls us to do the extraordinary for Him when he knows we are ready to be obedient to His call no matter what the cost!
I hope this encourages and challenges you as much as it has both encouraged and challenged me.