First Reading Acts 1:15-17, 20a, 20c-26
Peter stood up in the midst of the brothers
—there was a group of about one hundred and twenty persons
in the one place —.
He said, “My brothers,
the Scripture had to be fulfilled
which the Holy Spirit spoke beforehand
through the mouth of David, concerning Judas,
who was the guide for those who arrested Jesus.
He was numbered among us
and was allotted a share in this ministry.
“For it is written in the Book of Psalms:
May another take his office.
“Therefore, it is necessary that one of the men
who accompanied us the whole time
the Lord Jesus came and went among us,
beginning from the baptism of John
until the day on which he was taken up from us,
become with us a witness to his resurrection.”
So they proposed two, Judas called Barsabbas,
who was also known as Justus, and Matthias.
Then they prayed,
“You, Lord, who know the hearts of all,
show which one of these two you have chosen
to take the place in this apostolic ministry
from which Judas turned away to go to his own place.”
Then they gave lots to them, and the lot fell upon Matthias,
and he was counted with the eleven apostles.
Responsorial Psalm Psalms 103:1-2, 11-12, 19-20
R. (19a) The Lord has set his throne in heaven.
Bless the LORD, O my soul;
and all my being, bless his holy name.
Bless the LORD, O my soul,
and forget not all his benefits.
R. The Lord has set his throne in heaven.
For as the heavens are high above the earth,
so surpassing is his kindness toward those who fear him.
As far as the east is from the west,
so far has he put our transgressions from us.
R. The Lord has set his throne in heaven.
The LORD has established his throne in heaven,
and his kingdom rules over all.
Bless the LORD, all you his angels,
you mighty in strength, who do his bidding.
R. The Lord has set his throne in heaven.
Second Reading 1 John 4:11-16
Beloved, if God so loved us,
we also must love one another.
No one has ever seen God.
Yet, if we love one another, God remains in us,
and his love is brought to perfection in us.
This is how we know that we remain in him and he in us,
that he has given us of his Spirit.
Moreover, we have seen and testify
that the Father sent his Son as savior of the world.
Whoever acknowledges that Jesus is the Son of God,
God remains in him and he in God.
We have come to know and to believe in the love God has for us.
God is love, and whoever remains in love
remains in God and God in him.
Alleluia Cf. John 14:18
R. Alleluia, alleluia.
I will not leave you orphans, says the Lord.
I will come back to you, and your hearts will rejoice.
R. Alleluia, alleluia.
Gospel John 17:11b-19
Lifting up his eyes to heaven, Jesus prayed saying:
“Holy Father, keep them in your name that you have given me,
so that they may be one just as we are one.
When I was with them I protected them in your name that you gave me,
and I guarded them, and none of them was lost
except the son of destruction,
in order that the Scripture might be fulfilled.
But now I am coming to you.
I speak this in the world
so that they may share my joy completely.
I gave them your word, and the world hated them,
because they do not belong to the world
any more than I belong to the world.
I do not ask that you take them out of the world
but that you keep them from the evil one.
They do not belong to the world
any more than I belong to the world.
Consecrate them in the truth. Your word is truth.
As you sent me into the world,
so I sent them into the world.
And I consecrate myself for them,
so that they also may be consecrated in truth.”
Source: https://bible.usccb.org/bible/readings/051224-Sunday.cfm