"proclaim the Gospel to every creature.”

they called them back and ordered them not to speak or teach at all in the name of Jesus.
Peter and John, however, said to them in reply,
“Whether it is right in the sight of God
for us to obey you rather than God, you be the judges.
It is impossible for us not to speak about what we have seen and heard.

-- Acts 4:13-21

The transmission of the Christian faith consists primarily in proclaiming Jesus Christ in order to lead others to faith in him. From the beginning, the first disciples burned with the desire to proclaim Christ: "We cannot but speak of what we have seen and heard." It And they invite people of every era to enter into the joy of their communion with Christ:

That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon and touched with our hands, concerning the word of life - the life was made manifest, and we saw it, and testify to it, and proclaim to you the eternal life which was with the Father and was made manifest to us- that which we have seen and heard we proclaim also to you, so that you may have fellowship with us; and our fellowship is with the Father and with his Son Jesus Christ. And we are writing this that our joy may be complete.

-- CCC 425