The answer
St. Mary believed in Christ's divinity, and that He was God's son, before His birth, right from the time of the Annunciation when the angel said to her: " that Holy One who is to be born will be called the Son of God.. " (Luke 1:35).
And St Elizabeth confirmed this fact when Virgin Mary visited her after becoming pregnant, and she said to Mary: ""Blessed are you among women, and blessed is the fruit of your womb!" (Luke 1:43) This shows that it was not only St Mary's belief, but Elizabeth's belief too. And this was evidence of Mary's faith.
In addition to all this, the miracles which Christ performed and the holy visions on the occasion of His birth, were things seen by St Mary besides all this.
I can confidently say that the Virgin Mary was the first person to believe in the divine nature of Christ.
Let us not forget that St. Mary had studied the Bible and knew the prophecy of Isaiah where it says: "The virgin shall conceive and bear a Son, and shall call His name Immanuel." (Is. 7:14) and also: " For unto us a Child is born, Unto us a Son is given; And the government will be upon His shoulder. And His name will be called Wonderful, Counselor, Mighty God, Everlasting Father, Prince of Peace." (Is. 9:6)
St. Mary understood that these holy verses applied to her and her son, and that all the wonderful things which were happening before her eyes confirmed this. It was these things which she was said to have treasured in her heart.
It was on account of this that Mary said: "henceforth all generations will call me blessed. " (Luke 1:48)
As for the second person who believed, that was St. Joseph the carpenter and that happened as a result of the angel's prophecy to him.
The third person was, of course Elizabeth and the fourth was John the Baptist, who suddenly leaped for joy in the womb of his mother because he was still within her at the time when Mary came to visit ((( and when Jesus was a tiny seed inside her.(((
[ 59 ]
Thrice-Blessed Pope Shenouda III of Blessed Memory