Irenaeus of Lyons, Against Heresies 3.1

We have come to know the plan of our salvation through others, through those by whom the Gospel reached us; indeed, they first preached it, and afterward, by the will of God, handed it down to us in the Scriptures, to serve as the foundation and pillar of our faith (1 Tim 3:15). It is not right to claim that they preached before they possessed perfect knowledge, as some dare to assert, boasting that they are correctors of the Apostles. For after our Lord rose from the dead, and they were clothed with power from on high when the Holy Spirit came upon them, they were filled with all things and gained perfect knowledge (Luke 24:49; Acts 1:8; John 16:13). They went out to the ends of the earth, proclaiming the good things that come to us from God and announcing heavenly peace to humanity, each of them possessing the Gospel of God (Mark 16:15; Acts 1:8; Rom 10:15; Eph 2:17). Thus Matthew published a written Gospel in the Hebrews' own language, while Peter and Paul were evangelizing at Rome and founding the Church. After their departure, Mark, the disciple and interpreter of Peter, handed down to us in writing the things Peter had proclaimed. Luke, a follower of Paul, set down in a book the Gospel that Paul preached. Afterwards John, the disciple of the Lord who had also reclined on His breast, published the Gospel while living at Ephesus in Asia (John 13:23; 21:20). All of these announced to us one God, the Maker of heaven and earth, proclaimed by the Law and the Prophets, and one Christ, the Son of God (Acts 4:24; 14:15; Rom 1:2-3). If anyone does not assent to them, he despises the partakers of the Lord, he despises Christ the Lord, he despises the Father as well, and he stands self-condemned, resisting and opposing his own salvation; this is what all heretics do (Luke 10:16; 1 John 5:10-12; John 12:48).