The Solemnity of Mary, the Mother of God: "Born of a woman"

When the fullness of time had come, God sent his Son,
born of a woman, born under the law,
to ransom those under the law,
so that we might receive adoption as sons.
As proof that you are sons,
God sent the Spirit of his Son into our hearts,
crying out, “Abba, Father!”
So you are no longer a slave but a son,
and if a son then also an heir, through God.

-- Gal 4:4-7

Mary is truly "Mother of God" since she is the mother of the eternal Son of God made man, who is God himself.

- CCC 509

Throughout the Old Covenant the mission of many holy women prepared for that of Mary. At the very beginning there was Eve; despite her disobedience, she receives the promise of a posterity that will be victorious over the evil one, as well as the promise that she will be the mother of all the living. By virtue of this promise, Sarah conceives a son in spite of her old age. Against all human expectation God chooses those who were considered powerless and weak to show forth his faithfulness to his promises: Hannah, the mother of Samuel; Deborah; Ruth; Judith and Esther; and many other women. Mary "stands out among the poor and humble of the Lord, who confidently hope for and receive salvation from him. After a long period of waiting the times are fulfilled in her, the exalted Daughter of Sion, and the new plan of salvation is established."

-- CCC 489

Saint Thomas Becket, martyr: "Whoever hates his brother is in darkness"

the darkness has blinded his eyes.

-- 1 Jn 2:3-11

Deliberate hatred is contrary to charity. Hatred of the neighbor is a sin when one deliberately wishes him evil. Hatred of the neighbor is a grave sin when one deliberately desires him grave harm. "But I say to you, Love your enemies and pray for those who persecute you, so that you may be sons of your Father who is in heaven."

-- CCC 2303

Holy Innocents, martyrs: "I lay down my life"

if we walk in the light as he is in the light, then we have fellowship with one another, and the Blood of his Son Jesus cleanses us from all sin.

-- 1 Jn 1:5—2:2

The Son of God, who came down "from heaven, not to do [his] own will, but the will of him who sent [him]", said on coming into the world, "Lo, I have come to do your will, O God." "And by that will we have been sanctified through the offering of the body of Jesus Christ once for all." From the first moment of his Incarnation the Son embraces the Father's plan of divine salvation in his redemptive mission: "My food is to do the will of him who sent me, and to accomplish his work." The sacrifice of Jesus "for the sins of the whole world" expresses his loving communion with the Father. "The Father loves me, because I lay down my life", said the Lord, "[for] I do as the Father has commanded me, so that the world may know that I love the Father."

-- CCC 606

Art: Giotto, Slaughter of the Holy Innocents

Feast of Saint John, Apostle and evangelist: "we have seen"

and testify to it
and proclaim to you the eternal life
that was with the Father and was made visible to us

--1 Jn 1:1-4

Jesus often draws apart to pray in solitude, on a mountain, preferably at night. He includes all men in his prayer, for he has taken on humanity in his incarnation, and he offers them to the Father when he offers himself. Jesus, the Word who has become flesh, shares by his human prayer in all that "his brethren" experience; he sympathizes with their weaknesses in order to free them. It was for this that the Father sent him. His words and works are the visible manifestation of his prayer in secret.

-- CCC 2602

Saint Stephen, first martyr: "You will be hated by all"

... because of my name, but whoever endures to the end will be saved.

-- Mt 10:17-22

Believing in Jesus Christ and in the One who sent him for our salvation is necessary for obtaining that salvation. "Since "without faith it is impossible to please [God]" and to attain to the fellowship of his sons, therefore without faith no one has ever attained justification, nor will anyone obtain eternal life 'But he who endures to the end.'"

-- CCC 161

December 24: “Blessed be the Lord"

... the God of Israel; for he has come to his people and set them free.

-- Lk 1:67-79

"There was a man sent from God, whose name was John." John was "filled with the Holy Spirit even from his mother's womb" by Christ himself, whom the Virgin Mary had just conceived by the Holy Spirit. Mary's visitation to Elizabeth thus became a visit from God to his people.

-- CCC 717

December 23: "O Emmanuel"

O EMMANUEL, God with us, Our King and Lawgiver, the expected of the nations and their Saviour: COME to save us, O Lord our God.

Lo, I am sending my messenger
to prepare the way before me;
And suddenly there will come to the temple
the LORD whom you seek,
And the messenger of the covenant whom you desire. Yes, he is coming, says the LORD of hosts.
But who will endure the day of his coming?
And who can stand when he appears? For he is like the refiner’s fire, or like the fuller’s lye. He will sit refining and purifying silver, and he will purify the sons of Levi, Refining them like gold or like silver that they may offer due sacrifice to the LORD.

Mal 3:1-4, 23-24

Following in the steps of the prophets and John the Baptist, Jesus announced the judgment of the Last Day in his preaching. Then will the conduct of each one and the secrets of hearts be brought to light. Then will the culpable unbelief that counted the offer of God's grace as nothing be condemned. Our attitude to our neighbor will disclose acceptance or refusal of grace and divine love. On the Last Day Jesus will say: "Truly I say to you, as you did it to one of the least of these my brethren, you did it to me."

-- CCC 678