Today, to start with, the Gospel surprises us: «Who is my mother? (Mt 12:48), wonders Jesus. It would seem the Lord is showing a contemptuous attitude towards Mary, his mother. Nothing of the sort! What Jesus wants to make quite clear is that, in his own eyes —God's eyes— the crucial value of a person does not lie on flesh and blood facts, but on the spiritual disposition to accept God's will: «Then He pointed to his disciples and said, ‘Look! Here are my mother and my brothers. Whoever does the will of my Father in heaven is for me brother, sister, or mother’» (Mt 12:49-50). At that time, God's will was for Jesus to evangelize those who were listening and for these ones to actually listen to him. This was a priority over any other value, no matter how dear. To abide by his Father's will, Jesus Christ had left Mary and now He was preaching far away from home.
But, who was ever more willing to abide by God's will than Mary? «‘I am the Lord's servant’, Mary answered. ‘May it be to me as you have said’» (Lk 1:38). This is why, St. Augustine says that Mary, first accepted God's word with a spirit of obedience and, only afterwards, she conceived it in her womb for the Incarnation.
In other words: God loves us as per our saintliness. The Virgin Mary is the most blessed, and, therefore, the most loved. However, God does not love us because we may be saints. It is rather the other way round: we are saints because He loves us. The first one to love is always our Lord (cf. 1Jn 4:10). Mary proves it when she says: «For He has looked upon his handmaid's lowliness» (Lk 1:48). In God's eyes our own lowliness is evident; but He wants to magnify us, to sanctify us.