Of the apostles, therefore, John and Matthew first instill faith into us; whilst of apostolic men, Luke and Mark renew it afterwards. These all start with the same principles of the faith, so far as relates to the one only God the Creator and His Christ, how that He was born of the Virgin, and came to fulfill the law and the prophets. Never mind if there does occur some variation in the order of their narratives, provided that there be agreement in the essential matter of the faith, in which there is disagreement with Marcion.
Tertullian
The Five Books Against Marcion, Book IV
Chapter II