First Reading

Isaiah 40:1-5, 9-11

1“Be consoled, be consoled, O my people!” says your God. 2Speak to the heart of Jerusalem, and call out to her! For her malice has reached its end. Her iniquity has been forgiven. She has received double for all her sins from the hand of the Lord. 3The voice of one crying out in the desert: “Prepare the way of the Lord! Make straight the paths of our God, in a solitary place. 4Every valley will be exalted, and every mountain and hill will be brought low. And the crooked will be straightened, and the uneven will become level ways. 5And the glory of the Lord will be revealed. And all flesh together will see that the mouth of the Lord has spoken.” 6The voice of one saying, “Cry out!” And I said, “What should I cry out?” “All flesh is grass, and all its glory is like the flower of the field. 7The grass has dried up, and the flower has fallen. For the Spirit of the Lord has blown over it. Truly, the people are like grass. 8The grass has dried up, and the flower has fallen. But the Word of our Lord remains for eternity.” 9You who evangelize Zion, climb a high mountain! You who evangelize Jerusalem, lift up your voice with strength! Lift it up! Do not be afraid! Say to the cities of Judah: “Behold, your God!” 10Behold, the Lord God will arrive in strength, and his arm will rule. Behold, his reward is with him, and his work is before him. 11He will pasture his flock like a shepherd. He will gather together the lambs with his arm, and he will lift them up to his bosom, and he himself will carry the very young.
Responsorial Psalm

Psalm 84

9I will listen to what the Lord God may be saying to me. For he will speak peace to his people, and to his saints, and to those who are being converted to the heart. 10So then, truly his salvation is near to those who fear him, so that glory may inhabit our land. 11Mercy and truth have met each other. Justice and peace have kissed. 12Truth has risen from the earth, and justice has gazed down from heaven. 13For so will the Lord give goodness, and our earth will give her fruit. 14Justice will walk before him, and he will set his steps upon the way.
Second Reading

2 Peter 3:8-14

8Yet truly, let this one thing not escape notice, most beloved, that with the Lord one day is like a thousand years, and a thousand years is like one day. 9The Lord is not delaying his promise, as some imagine, but he does act patiently for your sake, not wanting anyone to perish, but wanting all to be turned back to penance. 10Then the day of the Lord shall arrive like a thief. On that day, the heavens shall pass away with great violence, and truly the elements shall be dissolved with heat; then the earth, and the works that are within it, shall be completely burned up. 11Therefore, since all these things will be dissolved, what kind of people ought you to be? In behavior and in piety, be holy, 12waiting for, and hurrying toward, the advent of the day of the Lord, by which the burning heavens shall be dissolved, and the elements shall melt from the heat of the fire. 13Yet truly, in accord with his promises, we are looking forward to the new heavens and the new earth, in which justice lives. 14Therefore, most beloved, while awaiting these things, be diligent, so that you may be found to be immaculate and unassailable before him, in peace.
Gospel Acclamation

Alleluia — Luke 3:4, 6

4just as it has been written in the book of the sermons of the prophet Isaiah: “The voice of one crying out in the wilderness: Prepare the way of the Lord. Make straight his paths. 5Every valley shall be filled, and every mountain and hill shall be brought low. And what is crooked shall be made straight. And the rough paths shall be made into level ways. 6And all flesh shall see the salvation of God.”
Gospel

Mark 1:1-8

1The beginning of the Gospel of Jesus Christ, the Son of God. 2As it has been written by the prophet Isaiah: “Behold, I send my Angel before your face, who shall prepare your way before you. 3The voice of one crying out in the desert: Prepare the way of the Lord; make straight his paths.” 4John was in the desert, baptizing and preaching a baptism of repentance, as a remission of sins. 5And there went out to him all the region of Judea and all those of Jerusalem, and they were baptized by him in the river Jordan, confessing their sins. 6And John was clothed with camel’s hair and with a leather belt around his waist. And he ate locusts and wild honey. 7And he preached, saying: “One stronger than me comes after me. I am not worthy to reach down and loosen the laces of his shoes. 8I have baptized you with water. Yet truly, he will baptize you with the Holy Spirit.”