In those days Mary arose and went with haste into the hill country, to a town in Judah, and she entered the house of Zechariah and greeted Elizabeth. And when Elizabeth heard the greeting of Mary, the baby leaped in her womb. And Elizabeth was filled with the Holy Spirit, and she exclaimed with a loud cry, "Blessed are you among women, and blessed is the fruit of your womb! And why is this granted to me that the mother of my Lord should come to me? For behold, when the sound of your greeting came to my ears, the baby in my womb leaped for joy. And blessed is she who believed that there would be a fulfillment of what was spoken to her from the Lord." (Luke 1:39-45 ESV)
"We must therefore be quite clear about why Elizabeth calls Mary blessed. It is because of the grace of God's Son whom she bore; and grace is something we all have in common with her. So what this passage reveals is that, while God was pleased to exalt the Virgin, having chosen her for the precious and noble task of bearing the Saviour of the world, he nevertheless wished to show how, in her person, we are all of us blessed.
"No-one denies that Mary was unique in being the mother of the Lord Jesus Christ. Yet as he himself declared, if we are joined to him by faith, he owns and acknowledges us as father, mother and brother (Matthew 12:49-50). What he means is that we have a relationship which is sufficient in itself. We do not need to be related to him in the way nephews, cousins, uncles, father, or mothers are. In order to receive us as members of his body, he asks only that we believe in him. There is no better union that that, which is why it ought to satisfy us. Indeed, the promise is made to all who receive Christ, that they are joined to him. Thus, because in him is fullness of blessing, we are freed from the curse which in Adam came upon the whole human race."
(John Calvin, Songs of the Nativity, translated by Robert White, Banner of Truth Trust, 2008, p. 13)
Painting above is The Visitation, by Philippe de Champaigne (ca. 1643), oil on canvas, on display at the Seattle Art Museum.