"Go into the whole world and proclaim the gospel to every creature"
After our Lord had been raised from the dead and the apostles had been clothed with power from on high by the coming of the Holy Spirit (Lk 24:49), they were filled with assurance concerning everything and understood perfectly. Then they, who together and individually had possession of the Gospel of God, went out to all the ends of the world (Ps 19[18]:5), proclaiming the Good News that has come to us from God and announcing peace on earth to men.
Thus Matthew made known a written form of the Gospel to the Hebrews in their own language, while Peter and Paul preached the Gospel in Rome and founded the Church there. After their death Mark, the disciple and interpreter of Peter (1Pt 5:13), himself handed on in writing Peter's preaching. While Luke, in his turn, the companion of Paul, set down in a book the Gospel preached by the latter. Finally, John, the disciple of the Lord, the same who rested on his breast, also published the Gospel during his stay at Ephesus...
Mark, who was Peter's interpreter and companion, presented the beginning of his version of the Gospel in this way: “The beginning of the Gospel of Jesus Christ, the Son of God. As it is written in the prophets: 'Behold, I am sending my messenger ahead of you; he will prepare your way'”... As can be seen, Mark makes the words of the holy prophets the beginning of his Gospel, and the one whom the prophets proclaimed as God and Lord, Mark places at the head as the Father of our Lord Jesus Christ... At the end of his Gospel, Mark says: “And the Lord Jesus, after he spoke to them, was taken up into heaven and took his seat at the right hand of God”. This confirms the prophet's words: “The Lord said to my Lord: 'Sit at my right hand till I make your enemies your footstool'” (Ps 110[109]:1).
Our Lady to Blessed Alan de la Roche