First Reading
REVELATION 7:2-4, 9-14

2Then I saw another angel ascend from the rising of the sun, with the seal of the living God, and he called with a loud voice to the four angels who had been given power to harm earth and sea, 3saying, "Do not harm the earth or the sea or the trees, till we have sealed the servants of our God upon their foreheads." 4And I heard the number of the sealed, a hundred and forty-four thousand sealed, out of every tribe of the sons of Israel, 9After this I looked, and behold, a great multitude which no man could number, from every nation, from all tribes and peoples and tongues, standing before the throne and before the Lamb, clothed in white robes, with palm branches in their hands, 10and crying out with a loud voice, "Salvation belongs to our God who sits upon the throne, and to the Lamb!" 11And all the angels stood round the throne and round the elders and the four living creatures, and they fell on their faces before the throne and worshiped God, 12saying, "Amen! Blessing and glory and wisdom and thanksgiving and honor and power and might be to our God for ever and ever! Amen." 13Then one of the elders addressed me, saying, "Who are these, clothed in white robes, and whence have they come?" 14I said to him, "Sir, you know." And he said to me, "These are they who have come out of the great tribulation; they have washed their robes and made them white in the blood of the Lamb.

Responsorial Psalm
PSALMS 24:1-6

1The earth is the LORD's and the fulness thereof, the world and those who dwell therein; 2for he has founded it upon the seas, and established it upon the rivers. 3Who shall ascend the hill of the LORD? And who shall stand in his holy place? 4He who has clean hands and a pure heart, who does not lift up his soul to what is false, and does not swear deceitfully. 5He will receive blessing from the LORD, and vindication from the God of his salvation. 6Such is the generation of those who seek him, who seek the face of the God of Jacob. [Selah]

Second Reading
1 JOHN 3:1-3

1See what love the Father has given us, that we should be called children of God; and so we are. The reason why the world does not know us is that it did not know him. 2Beloved, we are God's children now; it does not yet appear what we shall be, but we know that when he appears we shall be like him, for we shall see him as he is. 3And every one who thus hopes in him purifies himself as he is pure.

Gospel
MATTHEW 5:1-12

1Seeing the crowds, he went up on the mountain, and when he sat down his disciples came to him. 2And he opened his mouth and taught them, saying: 3"Blessed are the poor in spirit, for theirs is the kingdom of heaven. 4"Blessed are those who mourn, for they shall be comforted. 5"Blessed are the meek, for they shall inherit the earth. 6"Blessed are those who hunger and thirst for righteousness, for they shall be satisfied. 7"Blessed are the merciful, for they shall obtain mercy. 8"Blessed are the pure in heart, for they shall see God. 9"Blessed are the peacemakers, for they shall be called sons of God. 10"Blessed are those who are persecuted for righteousness' sake, for theirs is the kingdom of heaven. 11"Blessed are you when men revile you and persecute you and utter all kinds of evil against you falsely on my account. 12Rejoice and be glad, for your reward is great in heaven, for so men persecuted the prophets who were before you.